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Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 6 Organisms and Populations

Plus Two Botany Organisms and Populations One Mark Questions and Answers

Question 1.
Zero growth means
(a) Natality balance mortality
(b) Natality is more than mortality
(c) Natality is less than mortality
(d) Natality is zero
Answer:
(a) Natality balance mortality

Question 2.
Different types of interactions and the nature of interactions between species A and B are given in column I and II respectively. Choose the correct answer key where they are matched.

Answer:
(c) 2 5 4 3 1

Question 3.
Which one of the following is not used for the construction of ecological pyramids?
(a) Dry weight
(b) Number of individuals
(c) Rate of energy flow
(d) Fresh weight
Answer:
(d) Fresh weight

Question 4.
In a pond there were 200 frogs, 40 more were born in a year. Calculate the birth rate of population.
Answer:
Birth rate = 40/200 = 0.2 offspring per year.

Question 5.
What is the cause of altitude sickness at high altitudes?
Answer:
Is due to the low atmospheric pressure of high altitudes that the body is unable to get enough oxygen.

Question 6.
Amensalism is an association between two species where:
(a) One species is harmed and other is benefitted
(b) One species is harmed and other is unaffected
(c) One species is benefitted and other is unaffected
(d) Both the species are harmed
Answer:
(c) One species is benefitted and other is unaffected.

Question 7.
According to Allen’s Rule, the mammals from colder climates have:
(a) Shorter ears and longer limbs
(b) longer ears and shorter limbs
(c) longer ears and longer limbs
(d) shorter ears and shorter limbs
Answer:
(c) longer ears and longer limbs

Question 8.
Lichens are the association of:
(a) bacteria and fungus
(b) algae and bacterium
(c) fungus and algae
(d) fungus and virus
Answer:
(c) fungus and algae

Question 9.
Salt concentration (Salinity) of the sea measured in parts per thousand is:
(a) 10-15
(b) 30-75
(c)  0-5
(d) 30-35
Answer:
(d) 30-35

Question 10.
Formation of tropical forests needs mean annual temperature and mean annual precipitation as:
(a) 18-25°C and 150-400 cm
(b) 5-15°C and 50-100 cm
(c) 30-50°C and 100-150 cm
(d) 5-15°C and 100-200 cm
Answer:
(a) 18-25°C and 150 – 400 cm

Question 11.
Observe the following statements. Select the correct one.
(a) Temperature increases progressively from equator towards the poles and from plain to mountain tops.
(b) Temperature is sub-zero level in polar areas and high altitude and increases to above 50°c in tropical desert in summer.
(c) In unique habitats such as thermal springs and deep sea hydrothermal vents average temperatures exceed 20°c.
(d) Mango trees grow in temperate countries like Canada and Germany.
Answer:
(a) Temperature is sub-zero level in polar areas and high altitude and increases to above 50°c in tropical desert in summer.

Question 12.
Cuscuta and vanda are growing on a mango tree. Which plant makes harm to the mango tree. Justify your answer.
Answer:
Cuscuta makes harm, it is a parasite that derives its nutrition from the host plant.

Question 13.
Which one of the following is not related to competition.
(a) Competition occurs when closely related species compete for the same resources that are limiting.
(b) Unrelated species also compete for same resources.
(c) Even if resources are abundant, the feeding effect of one species might be reduced due to the interfering and inhibitory presence of other species.
(d) Calotropis. growing in abandoned fields is an example of competition.
Answer:
(d) Calotropis growing in abandoned fields is an example of competition.

Question 14.
Parasitic mode of life ensures free lodging and meals. Identify the correct statements related to parasites.
(a) Parasites are not host specific and co-evolved.
(b) Parasites have special adaptations like loss of unnecessary sense organs, presence of suckers, loss of digestive systems, high reproductive capacity.
(c) Lice is an endoparasite.
(d) The female mosquito is a parasite.
Answer:
a, b.

Question 15.
Observe the relationship between the first two terms and fill in the blanks. Hibernation: Bear;……….: Snail
Answer:
Aestivation.

Question 16.
Read the statements properly and choose the correct one.
(a) Many desert plants have CAM pathway that enables their stomata to remain open during day time.
(b) In Opuntia, leaf reduced into green flattened structure.
(c) Kangaroo rat in North American deserts is capable of meeting all water requirements through the protein oxidation.
(d) Mammals from colder climate generally have shorter ears and limbs.
Answer:
(d) Mammals from colder climate generally have shorter ears and limbs.

Plus Two Botany Organisms and Populations Two Mark Questions and Answers

Question 1.
In a biotic community initially the population size was 250 during the year 2005 after a period of time 130 animals died of forest fire 20 were nearly born. During the next winter season 20 animals immigrated. Find out the change in population size.
Answer:
Nt = No + B + I – D + E
Therefore Nt = 250+ 20+ 20- 130 + 40
= 290- 170= 120

Question 2.
Some organism are different intheirtoleration level to temperature fluctuations

1. Name the type of organism that can tolerate wide range of temperature variation especially in increased global temperature?
2. Name the other type organisms restricted to narrow range.

Answer:

1. Eurythermal species,
2. Stenothermal.

Question 3.
In desert condition water availability very low hence normal plants cannot withstand. What are the adaptations are desert plants.
Answer:

1. Thick cuticle on their leaf surfaces
2. Stomata arranged in deep pits to minimise water loss through transpiration.
3. They show CAM pathway (they open stomata during night and closed during day time)
4. Opuntia, their leaves are reduced to spines and the flattened stems do photosynthesis.

Question 4.
In extreme summer and winter certain animals like frogs and lizard abandon their active life. This is popularly known as summer sleep and winter sleep respectively. Write down the technical term for summer sleep and winter sleep.
Answer:

• Summer sleep – Aestivation
• Winter sleep – Hibernation

Question 5.
What you meant by resource partitioning in an ecosystem.
Answer:
If two species compete for the same resource, they avoid competition by choosing different times for feeding or different foraging patterns.This is called resource partitioning.

Question 6.
Camouflaging is a method adopted by prey to lessen effect of predatien in animals. List out some mechanisms seen in plant species.
Answer:
Plants have evolved a variety of morphological and chemical defences against their predators (herbi-vores).

1. Thorns in plants are morphological means of defence.
2. Plants produce and store chemicals that make the herbivore sick. Eg: Glycosides, Quinine, Caf¬feine, Opuim etc.

Question 7.
Gause proposed the Competitive Exclusion Principle in 1934.

1. Define it
2. Give an example.

Answer:
1. Competitive Exclusion Principle states that the closely related species competing for the same resources cannot co-exist indefinitely The competitively inferior one will be eliminated eventually.

2. Abingdon tortoise compete with goats in galapagos island for same food source and tortoise became extinct.

Question 8.
Many tribes living in high altitudes of Himalayas have higher red blood cell count.

1. Do you agree?
2. Give reason

Answer:
1. Yes.

2. In high altitudes there is low oxygen availability. The tribes having high RBC production since the binding capacity of RBC with 02 decreases and ultimately results in high breathing rate.

Question 9.
Tribalsin high altitude are difficult to live in the initial phase of colonization but after few days they are adapted to live.

1. Write down 2 adaptations they developed
2. Name two disease symptoms in low 02 and atmospheric pressure conditions

Answer:
1. 2 adaptations they developed:

• increase RBC production
• increase breathing rate

2. nausea, fatigue.

Question 10.
The relationship between cattle egret and grazing cattle is considered as commensalism. Justify.
Answer:
Cattle egret gets food in the form of insects when the grazing cattle flushes out insects from the vegetation as it moves during grazing. The egret is benefited but there is no harm for the cattle.

Question 11.
Abingdon tortoise and goats are compete with each other in Galapagos Islands for common food finally one of them is eliminated.

1. Name the principle proposed by Gause to explain the elimination of one species due to other
2. Suggest one important method to reduce competition

Answer:

1. competitive exclusion principle
2. resource partitioning

Question 12.
Thermoregulation is expensive to small animals like Shrews and Hummingbirds live in colder climates. Do you agree? Give reason.
Answer:
Yes
Their body surface area is large compared to body volume, hence they have to spend more energy to increase metabolic rate when cold outside for producing more heat.

Question 13.
Ophrys is a Mediterranean orchid it’s petals shows resemblance to female be in colour size and markings but a male bee come into the flower and pollinate

1. Name the sexual deciet between male bees and orchid
2. Which is the interaction used to explain pollination method mentioned above

Answer:

1. pseudocopulation
2. mutualism

Question 14.
In sample A population growth under abandoned food supply violin sample B population growth under reduced food supply.

1. Name the two types of growth occurs in sample A and sample B
2. What will be the shape of curve get in sample A and sample B population

Answer:

1. In sample A exponential growth, in sample B Logistic growth
2. In sample A- J shaped, In sample B- S shaped

Question 15.
dN/dt = (b-d) × N
Let (b-d) = r, then
dN/dt = rN

1. What does r indicate in the above equation?
2. Which parameter is chosen for assessing impact of any biotic or abiotic factor on population growth?

Answer:

1. Intrinsic rate of natural increase
2. r parameter

Question 16.
Use proper terms of the statement given below.

1. Few organisms can tolerate and thrive in wide range of temperature.
2. Some organisms are tolerant to a narrow range of salinities.
3. The organism should try to maintain the constancy of its internal environment.
4. The organism may move temporarily from the stressful habitats to more hospitable area and return when stressful period is over.

Answer:

1. Eurythermal
2. Stenothermal
3. Homeostasis
4. Migrate

Question 17.
The integral form of the exponential growth equation is Nt = N₀e^rt. Expand the symbols in this equation.
Answer:

• Nt – Population density at time t
• No – Population density at time 0
• r – Intrinsic rate of natural increase
• e – base of natural logarithms.

Question 18.
In rocky intertidal communities of the American Pacific Coast the starfish Pisasterwere removed for an experimental purpose.

1. How did this affect the invertebrates in that region?
2. List out the important role of predators in nature.

Answer:
1. Pisaster is an important predator in the intertidal area. When Pisasters were removed, more than 10 invertebrate species became extinct because of interspecific competition.

2. important role of predators in nature:

• Predation helps to transfer energy to higher trohpic level from plants,
• Agricultural pest control or biological control is based on the ability of predator that important in regulating prey population.

Question 19.
Match A with B based on mutualism.

Answer:

• Lichen – cyanobacteria
• Mycorrhiza – fungi
• Fig tree – Wasp
• Sexual deceit – Ophrys

Question 20.
Define commensalism and write any two examples.
Answer:
Interaction in which one species benefited and the other is neither harmed nor benefited.
Example – Cattle egret and grazing cattle Sea anemone and clownfish.

Question 21.
Adaptations may be morphological, physiological or behavioural. Write the behavioural adaptations in desert lizard.
Answer:
Desert lizards bask in the sun and absorb heat when their body temperature drops below the comfort zone They move into shade when the temperature starts increasing.

Question 22.
Interaction between sea anemone and clown fish is termed as commensalism. Substantiate this statement.
Answer:
Sea anemone has stining tentacles and the clown fish lives among them, In this interaction the fish get protection from predators which stay away from the stinging tentacles but sea anemone does not derive any benefit or harm by hosting the clown fish.

Question 23.
Competition causes extinction of species. Substantiate this statement based on the extinction of Abingdon tortoise.
Answer:
A bingdon tortoise in Galapagos islands became extinct due to the introduction of goat on the island because goats have greater browsing efficiency than tortoise. Due to the lack of food tortoise became extinct.

Plus Two Botany Organisms and Populations Three Mark Questions and Answers

Question 1.
Given below is the bar diagram showing the age structure of three countries. Answer the following questions by analyzing the diagram.

1. Which country has the highest population?
2. Which country has declining population?
3. One of the countries has a stable population. Explain.

Answer:

1. A has the highest population
2. C has declining population
3. B has stable population. In this population reproductive and pre-reproductive individuals are more or less same. Hence it is stable.

Question 2.
Population growth curves (two types are given: observing the graph answer the following questions).

1. Identify the curves a & b.
2. Explain the signficance of K.
3. Which population growth has limited food supply?

Answer:

1. Curve ‘a’ is exponential growth curve and b is logistic growth curve.
2. K is the carrying capacity. Beyond K no further growth of population is possible.
3. Logistic growth

1. Name A, B and C pyramids.
2. Which one is ideal for a population. Suggest reason.
3. How does such age pyramids help policy makers of the country.

Answer:
1. Name A, B and C pyramids:

• Expaning
• Stable
• Declining

2. Expanding
Pre reproductive individuals are more in number than reproductive and post-reproductive.

3. It reflects the growth status

Question 4.
Scientist paul Ehrlich and Peter Raven developed the concept of co-evolution.

1. Give an example for co-evolution.
2. How did they show mutualistic association.
3. Name the mutualistic relationship shown by male bee and ophrys petal.

Answer:
1. Wasp and fig tree.

2. The female wasp lays its egg in the ovary locule and uses the developing seeds within the fruit for nourishing its larvae. The wasp pollinates the fig inflorescence while searching for suitable egg laying sites.

3. Pseudocopulation

Question 5.
Analyze the given graph which represents the population growth curve.

1. Which growth curves do ‘a’ and ‘b’ indicate?
2. Suggest an equation for ‘b’.
3. What parameters are required for calculating current r-value?

Answer:
1. growth curves do ‘a’ and ‘b’ indicate

• Exponential growth curve
• logistic growth curve

2. \(\frac{\mathrm{d}\mathrm{N}}{\mathrm{dt}}=\mathrm{rN}\left(\frac{\mathrm{K}-\mathrm{N}}{\mathrm{K}}\right)\)

3. Current birth rate and death rate.

Question 6.
Observe the flow chart given below and answer the following questions.

1. Identify I, B, D and E.
2. Write the equation for population density.
3. B and I are positive, D and E are negative about population. Suggest reason.

Answer:
1. Identify I, B, D and E:

• l-Immigration
• D-Mortality
• B-Natality
• E-Emigration

2. N_t+1 = Nt + [(B+1)-(D + E)]

3. N and I are natality and immigration – Both contribute an increase in population density. D and E are mortality and emigration – Both contribute to decrease in population.

Question 7.
Analyse the given graph and answer the following questions.

1. Label a, b, c.
2. How a differs from b?

Answer:
1.

• Conformers
• Regulators
• Partial regulators

2.

• Organism Cannot maintain constant internal environment.
• Organism can maintain constant internal environment through thermoregulation and osmoregulation.

Question 8.
Fill in the blanks.

Answer:
(a) Mutualism
(b) Competition
(c) Predation
(d) Parasitism
(e) Commensalism
(f) Amensalism

Plus Two Botany Organisms and Populations NCERT Mark Questions and Answers

Question 1.
Define phenotypic adaption. Give one example.
Answer:
Phenotypic adaptions are acquired non-genetic changes in individuals such as physiological modification, acclimatization or behavioural changes.

For examples, if a person has ever been to any high altitude, on visiting such as place he or she must have altitude sickness because body does not get enough oxygen. But gradually he or she gets acclimatized and stop experiencing altitude sickness.

Question 2.
Most living organisms cannot survive at temperature above 45°C. How are some microbes able to live in habitats with temperature exceeding 100°C?
Answer:
The microbes of high temperature area are known as thermo-acidophiles. They are able to survive at high temperature through.

1. Reduction in amount of free water.
2. Occurrence of branched chain lipids that reduce fluidity of cell membranes.

Question 3.
List the attributes that populations but not individuals possess.
Answer:

• Population density.
• Natality or birth rate.
• Mortality or death rate.
• Population growth.
• Sex ratio.
• Age distribution.

Question 4.
If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
Answer:
N_t = N₀ e^rt
Since N_t = 2; N0 = 1, e = 2.71828 ; t = 3
2 = (1 × 2.71828)^3r
Log 2 = 3 r log (2.71828)
0.3010 = 3 r × 0.4343
r= 0.2310
Intrinsic rate of increase=23.1 %.

Question 5.
Name important defence mechanisms in plants against herbivory?
Answer:
Leaves modified into thorns, development of spiny margins on the leaves. Many plants produce and store chemicals that make the herbivore sick.

eg: calotropis produces highly poisonous cardiac glycosides. Some other chemical substances like nicotine, quinine, opium etc are produced by plants and provide defence against grazing animals.

Question 6.
An orchid plant is growing on the branch of mango tree. How do you describe this interaction?
Answer:
It is an example of commensalism, where the or-chid gets space (benefitted) but the mango tree is neither benefited nor harmed.

Question 7.
What is the ecological principle behind the biological control method of managing with pest insects?
Answer:
The ecological principle behind the biological control of pest insects is based on the ability of predator to regulate prey population in that habitat. For example Gambusia fish prey upon the larvae of mosquito and acts as biological controller of malaria.

Plus Two Botany Organisms and Populations Multiple Choice Questions and Answers

Question 1.
The niche of a population is defined as
(a) set of condition that interacts
(b) place where it lives
(c) set of conditions and resources it uses
(d) geographical’ area that it covers
Answer:
(c) set of conditions and resources it uses

Question 2.
Competition for food, light and space is most severe between two
(a) closely related species growing in different niches
(b) distantly related species growing in different niches
(c) closely related species growing in same niches
(d) distantly related species growing in same niches
Answer:
(c) closely related species growing in same niches

Question 3.
An ecosystem, which can be easily damaged but can recover after some time if damaging effect stops, will be having
(a) low stability and high resilience
(b) high stability and low resilience
(c) low stability and low resilience
(d) high stability and high resilience
Answer:
(a) low stability and high resilience

Question 4.
Assertion: Predaton is an interspecific ineraction with I a feeding strategy.
Reason: Predation and their prey maintain fairly stable population become abundant or scarce.
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
(c) Assertion is true but Reason is false
(d) Both Assertion and Reason are false
Answer:
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion

Question 5.
The assemblage of all the populations of different species that function as an Integrated unit through coevolved metabolic transformation in a specific area is Called
(a) biome
(b) biotic community
(c) population
(d) ecosystem
Answer:
(b) biotic community

Question 6.
A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this
I) Lots of urea and phosphate fertilizers were used in the crops in the vicinity.
II) The area was sprayed with DDT by an aircraft
III) The lake water turned green and stinky.
IV Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis. Which two of the above were the main causes of fish mortality in the lake?
(a) II, III
(b) III, IV
(c) I, III
(d) I, II
Answer:
(d) I, II

Question 7.
In commensalism
(a) both partners are harmed
(b) weaker partner is benefitted
(c) both partners are benefitted
(d) None of the partners is benefited
Answer:
(b) weaker partner is benefitted

Question 8.
If the strong partner is benefitted and the weak partner is damaged. It is known as
(a) predation
(b) alleloathy
(c) symbiosis
(d) commensalisms
Answer:
(a) predation

Question 9.
Competition of species leads to
(a) extinction
(b) mutation
(c) greater number of niches are formed
(d) symbiosis
Answer:
(a) extinction

Question 10.
Which of the following statement regarding species interdependence are true?
I. An association of two species where one is benefitted and other remain unaffected is called mutualism.
II. An interspecific association where both partners derive benefit from each other is called commensalism.
III. A direct food relation between two species of animals in which one animals kills and feeds on another is referred as predation.
IV. A relationship between two of organisms where both the partners are benefitted from each other is called symbiosis.
(a) I and II only
(b) III and IV only
(c) I and III only
(d) II and III only
Answer:
(b) III and IV only

Question 11.
In India, human population is heavily weighed towards the younger age group as a result of
(a) Short life span of many individuals and low birth rate
(b) Short life span of many individuals and high birth rate
(c) long life span of many individuals and high birth rate
(d) long life span of many individuals and low birth rate
Answer:
(b) Short life span of many individuals and high birth rate

Question 12.
Ratio between mortality and natality is
(a) population ratio
(b) census proportion
(c) vital index
(d) density coefficient
Answer:
(c) vital index

Question 13.
The population of an insect species shows an explosive increase in number during rainy season followed by its disappearance at the end of the season. What does this show?
(a) S-shaped or sigmoid growth of this insect
(b) The food plants mature and die at the end of the rainy season
(c) Its population growth curve is of type
(d) The population of its predators increases enormously
Answer:
(c) Its population growth curve is of type

Question 14.
The annual variations in temperature results distinct seasons, these variations together with annual variation in precipitation leads to
(a) rain forest
(b) deserts ,
(c) lake
(d) both a and b
Answer:
(d) both a and b

Question 15.
Few organisms can tolerate and thrive in a wide range of temperatures they are called as
(a) eurythermal
(b) stenothermal
(c) euryhaline
(d) stenohaline
Answer:
(a) eurythermal

Question 16.
The type of benthic animals in ocean is determined by
(a) pH of water
(b) mineral composition
(c) sediment characteristics
(d) dissolved CO„ level
Answer:
(c) sediment characteristics

Question 17.
Important characteristics of mammals live in Antarctica or in the Sahara desert have
(a) osmoregulation
(b) thermoregulation
(c) thermoperiodicity
(d) both a and b
Answer:
(d) both a and b

Question 18.
The Smaller animals have a larger surface area, so they tend to lose body heat very fast when it is cold outside. This result in spending
(a) much energy for catabolism
(b) much energy for catabolism and anabolism
(c) low energy for catabolism
(d) much energy for anabolism
Answer:
(b) much energy for catabolism and anabolism

Question 19.
The Keolado National Park in Rajasthan host many
(a) bat population from warmer countries
(b) bird population from warmer countries
(c) bird population from winter countries
(d) bat population from winter countries
Answer:
(c) bird population from winter countries

Question 20.
Mammals of colder climates have shorter ears and limbs to minimise heat loss. This is come under
(a) Allen’s Rule
(b) bergmans rule
(c) jordans rule
(d) none of the above
Answer:
(a) Allen’s Rule

Question 21.
The number of births plus the number of immigrants is the major component in determining the
(a) density of population
(b) sex ratio
(c) age distribution
(d) species composition
Answer:
(a) density of population

Question 22.
If the resources in the habitat are unlimited, this results in the population have
(a) s- shaped curve
(b) j shaped curve
(c) parabolic curvature
(d) linear curve
Answer:
(b) j shaped curve

Question 23.
The equation dN/dt = rN(K-N/K) is represented as
(a) logistic population growth
(b) exponential population growth K
(c) Verhulst-Pearl Logistic Growth
(d) both a and c
Answer:
(d) both a and c

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Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 5 Biotechnology and its Applications

Plus Two Botany Biotechnology and its Applications One Mark Questions and Answers

Question 1.
Transgenic cotton plant which is resistant to boll worm got the gene from
(a) Bacillus thuringiensis
(b) Spirulina
(c) Dictyostelium
(d) Trichonympha
Answer:
(a) Bacillus thuringiensis

Question 2.
A multinational company outside India tried to sell new varieties of turmeric without proper patent rights. What is such an act referred to?
Answer:
Biopiracy

Question 3.
Name the biological product that obtained from transgenic cow Rosie.
Answer:
Human Alpha Lactalbumin

Question 4.
Name the technique used to prevent the attack of nematode in root of tobacco plants
Answer:
RNA interference

Question 5.
Which is most important method used to correct the genetic defect.
Answer:
Gene therapy

Question 6.
Some times genetically modified organisms will make unpredictable results in future. Which is the organisation of Govt, of India monitor the validity of GM research
Answer:
GEAC (Genetic Engineering Approval Committee)

Question 7.
Give an example for organism that possess acidic PH in their stomach?
Answer:
Humans

Question 8.
An important food crop developed by genetic engineering technique solve the problem of it. A deficiency. Name it.
Answer:
Golden rice

Question 9.
The site of production of ADA in the body is:
(a) Bone marrow
(b) lymphocytes
(c) Blood plasma
(d) Monocytes
Answer:
(b) lymphocytes.

Question 10.
In RNAi, genes are silenced using:
(a) ss DNA
(b) ds DNA
(c) ds RNA
(d) ss RNA
Answer:
(c) ds RNA

Question 11.
The first clinical gene therapy was done for the treatment of
(a) AIDS
(b) Cancer
(c) Cystic fibrosis
(d) SCID (Servere Combined Immuno Deficiency resulting form deficiency of ADA)
Answer:
(d) SCID (Servere Combined Immuno Deficiency resulting form deficiency of ADA)

Question 12.
ADA is an enzyme which is deficient in a genetic disorder SCID. What is the full form of ADA?
(a) Adenosine deoxy aminase
(b) Adenosine deaminase
(c) Aspartate deaminase
(d) Arginine deaminase
Answer:
(b) Adenosine deaminase

Question 13.
Siliencing of a gene could be achieved through the use of
(a) Short interfering RNA (RNAi)
(b) Antisense RNA
(c) By both
(d) None of the above
Answer:
(c) By both

Question 14.
Which among the following plants is related with the issues of biopiracy?
(a) Bt cotton
(b) Basmati Rice
(c) Atlas 66
(d) Bt Brinjal
Answer:
(b) Basmati Rice

Question 15.
What is the major disadvantage of insulin taken from slaughtered cattle and pigs?
Answer:
It causes allergy and other types of reactions

Question 16.
Disorder due to ADA deficiency can be over came by…………….
(a) RNA interference
(b) PCR
(c) ELISA
(d) Gene Therapy
Answer:
(b) Gene Therapy

Question 17.
Bacillus thuringiensis produces insecticidal proteins. Why does this protein not kill the Bacillus?
Answer:
Bt toxin exist as inactive protoxins

Question 18.
Very low concentration of DNA of pathogen can be amplified and hence diagnosis becomes easy. Which method is suitable for this method?
Answer:
PCR (Polymerase Chain Reaction)

Question 19.
Which among the following plants is related with the issues of biopiracy?
(a) Bt cotton
(b) Basmati Rice
(c) Atlas 66
(d) Bt Brinjal
Answer:
(b) Basmati Rice

Question 20.
Crystals of Bt toxin produced by Bacillus thuringiensis do not kill the bacteria themselves because.
(a) Bacteria is resistant to toxin
(b) Toxins only kill animals
(c) Toxin is inactive
(d) Toxin is protein
Answer:
(c) Toxin is inactive

Question 21.
What is the major disadvantage of insulin taken from slaughtered cattle and pigs?
Answer:
It causes allergy and other types of reactions.

Question 22.
RNAi was first introduced in tobacco plants to restrict the infection of a nematode worm………..
Answer:
Meloidegyne incognitia

Question 23.
Manipulation of living organisms by the human race cannot go on any further, without regulations. Which committee in India makes decisions regarding GM research?
Answer:
GEAC (Genetic Engineering Approval Committee).

Plus Two Botany Biotechnology and its Applications Two Mark Questions and Answers

Question 1.
Write the two uses of PCR technique.
Answer:

1. It is used to detect HIV in suspected AIDS patients.
2. It is being used to detect mutations in gene in suspected cancer patients.

Question 2.
Bone marrow transplantation is not permanent cure for ADA deficiency why?
Answer:
Bone marrow transplantation is not permanent cure because the differentiated cells stops the production of ADA after the definite period.

Question 3.
In 1997 American Government got patent for producing a trasgenic plant.

1. Name the plant.
2. What are the evidences to show that Basmathi rice has been grown in India from centuries?

Answer:

1. Basmathi rice.
2. There are references of Basmathi rice in ancient texts, folklores, and poetry.

Question 4.
List out the advantages of genetically modified crops.
Answer:
Advantages

1. GM crops are more tolerant to abiotic stresses, Reduce post harvest loss
2. Increase efficiency of mineral usage
3. Increase nutritional value.
4. To supply alternate resources in the form of starches, fuels, and pharmaceuticals.

Question 5.
Bacillus thuringiensis produce insecticidal proteins. Called Bt toxins. Explain how Bt toxins works in insects and kill them.
Answer:
Inactive protoxin produced by Bacillus thuringinsis becomes active at the alkaline PH of the insect gut, the activated toxin binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis.

Question 6.
Bt plants are genetically engineered insect resistant plants.

1. What does ‘Bt’ stand for?
2. Cite examples for any two ‘cry’ genes which produce Bt toxin.

Answer:

1. Bacillus thuringiensis
2. Cry I Ac, Cry II Ab.

Question 7.
Serious problems are associated with conventional agriculture.

1. Identify the problems
2. How is it solved?

Answer:
1. Low crop yield

• Use of expensive agrochemicals.
• The harmful effects of agrochemicals on the environment.

2. These problems can be solved by using genetically modified crops.

Question 8.
Why the crystals of Bt toxin do not kill the bacteria themselves?
Answer:
The toxin is active only at certain alkaline pH inside the gut of the insect. The toxin is inactive inside the bacteria as it exists as protoxin.

Question 9.
Cry genes are of different types.

1. Name 3 cry genes.
2. Write the uses of proteins produced by these genes?

Answer:

1. Cry I Ac, Cry ll Ab, Cry lAb
2. Cry IAc& Cry ll Ab – Produces toxic protein to control cotton boll worm Cry lAb – Produce toxic protein to control corn borer.

Question 10.
Insulin in man is normally produced by the (3 cells of the pancreas. But now a days it is commercially produced from bacteria like E.coli and marketed as ‘humulin’.

1. Write down the procedure used
2. Insulin is not taken from pancreas of slaughtered animals. Why?

Answer:
1. Human insulin was synthesized by American company Eli Lilly by recombinant DNA technology. The 2 DNA sequence coding for A & B polypeptide chain were introduced into E coli. The 2 polypeptide chains are synthesized independently and later linked by disulphide bond to form mature insulin.

2. It causes allergy

Question 11.
Specific genes of nematode are introduced into Tobacco plant through the vector.

1. Identify the used vector in above case.
2. Explain the role of that introduced gene in the Tobacco plant.

Answer:

1. Agrobacterium tumifaciens.
2. Offers resistance to the plant by silencing mRNA by the process of RNA interference.

Question 12.
The conventional methods are used for curing ADA deficiency. Identify the conventional methods. Write its demerits.
Answer:
Conventional methods of disease diagnosis like serum and urine analysis are not able to detect low concentration of viruses and other pathogens.

Question 13.
How can PCR detect very low amounts of DNA?
Answer:
PCR is a Polymerase Chain Reaction, which amplifies low amount of DNA making multiple copies of which it helps in the diagnosis of low amount of DNA.

Question 14.
Match the following.

Answer:

Question 15.
Insulin in man is normally produced by Beta cells of pancreas. But now a days it is commercially produced from bacteria like E. coli and marketed as Humulin. Explain how this method is possible.
Answer:
An American company Eli Lilly in 1983 prepared two. DNA sequences corresponding to A and B, chains of human insulin and inserted in plasmids of E. coli to produce insulin chains. Chains A and B were produced separately, extracted and combined by creating disulfide bonds to form human insulin.

Question 16.
One of the applications of biotechnology is the corrective therapy for hereditary diseases.

1. Do you agree with this? Which technique is used to achieve this?
2. How can this be done?

Answer:

1. Yes.Gene therapy
2. In gene therapy, lymphocytes from the blood of the patient are cultured and functional ADA cDNA is introduced in it. Then, these cells are return back to the patient. These cells can produce adenosine deaminase enzyme.

Question 17.
A nematode is found to be infecting the root of tobacco plant and there by decreasing the yield. Mention a novel technology adopted to check the infestation.
Answer:
The best method used to prevent the attack of nematode is RNA interference (RNAi), It involves silencing of a specific mRNA of nematode.

Question 18.
GM crops prevents early exhaustion of fertility of soil. Give reason.
Answer:
GM crops have the ability to resist diseases So the use of chemical pesticide can be decreased. This helps to keep the nitrogen fixing and other useful microbes in the soil as live.

Question 19.
Suppose you have produced a GM plant. Which Govt, organisation will take decisions regarding the validity of your genetic research? Why is such a body necessary?
Answer:
GEAC (Genetic Engineering Approval Committee) They take decisions regarding the validity of GM research and the safety of introducing GM- organisms for public services.

Question 20.
Recently you heard a lot about HiNi virus from medias. PCR technique is used for proper diagnosis of the disease by our research institutes. What is the significance of PCR technique in the early diagnosis of H1N1?
Answer:
This technique is used for amplify the viral nucleic acid up to 1 billion copies. This helped in the early diagnosis of diseases.

Question 21.
Name the factors on which behavior of genetically modified organism (GMO) depends.
Answer:
The behavior of GM organism depends on the nature of genes transferred, nature of host plant and animal or bacterium.

Question 22.
What is a DNA probe?
Answer:
DNA probe is a small DNA segment that recognize complementary sequence in DNA molecule and allow identification and isolation of specific DNA sequence from an organism.

Question 23.
Write the two uses of PCR technique.
Answer:

1. It is used to detect HIV in suspected AIDS patients
2. It is being used to detect mutations in gene in suspected cancer patients.

Question 24.
How patent is given?
Answer:
Patent is given to

1. For producing new product or invention.
2. Modified and improved earlier invention.
3. Technical know how.
4. New designing concept.

Question 25.
Give example of vaccine safety in respect to transgenic animals.
Answer:
Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of polio vaccine

Question 26.
Which three options could be thought for increasing food production?
Answer:

1. Agro – chemical-based agriculture
2. Organic agriculture
3. Genetically engineered crop-based agriculture.

Question 27.
What are genetically modified organisms (GMO)?
Answer:
Organisms such as plants, bacteria, fungi, and animals whose genes have been manipulated are known as GMO.

Question 28.
What was the speciality of the milk produced by the transgenic cow Rosie?
Answer:
Contains Human alpha-lactalbumin. Nutritionally more balanced than normal cow milk.

Question 29.
Explain why Bt cotton flowers undergo pollination by butterflies and bees in spite of being insect pest resistance.
Answer:
cotton is genetically engineered to produce a toxin which kills insect pests which eat the plant and cause the damage. Bees and butterflies only forage for nectar in flowers and do not eat any part of the plant so they do not die.

Question 30.
An important food crop developed by genetic engineering technique solve the problem of vitA deficiency.
Answer:
Golden rice is genetically engineered with vitA precursor of carotenoids.

Question 31.
RNA interference takes place in all eukaryotic organisms as a metffod of cellular defense. What is RNA interference?
Answer:
It is the silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation or protein synthesis of mRNA.

Question 32.
Pest resistant plants can be developed by genetic engineering. Explain how RNAi is successful in this area?
Answer:
In this process, nematode specific genes are introduced into the host plant through agrobacterium, it produce both sense and antisense RNA, since this two RNAs are complementary to each other, form a dsRNA, RNAi is operated and the nematode can’t produce proteins.

Question 33.
Given below is the diagram showing formation of insulin from pro-insulin. Explain how proinsulin develops to form insulin?

Answer:
Proinsulin is an immature and non functional that contains A, B and C chains, it is matured into insulin by the removal of short c peptide chain.

Question 34.
The first clinical gene therapy was given in 1990 to a four-year-old girl with ADA deficiency.

1. Write the steps involved in this method of treatment.
2. What is the major disadvantage of this process?

Answer:
1. In this method Lymphocytes taken from the blood of the patient and grown in a culture outside the body, into these, functional ADA cDNA are introduced, after this modified lymphocytes are returned back into the patients body.

2. Since the lymphocytes are not immortal, patient requires periodic infusion of genetically engineered lymphocytes.

Question 35.
Given below are two laboratory methods used for molecular diagnosis PCR, ELISA.

1. Expand PCR and ELISA
2. What is the principle of ELISA

Answer:

1. Polymerase Chain Reaction Enzyme Linked Immuno Sorbent Assay
2. Antigen-antibody interaction.

Question 36.
Given below are some biological products, which are produced by transgenic organisms

• a -1 – antitrypsin
• a-lactalbumin
• human insulin

1. Fill in the column given below suitably using the above terms

2. ……….is the transgenic cow, which produces human milk protein.
Answer:
1. A = human insulin
B = α lactalbumin
C = α-1-antitrypsin

2. Rosie

Question 37.
Genetically modified plants have been useful in many ways. Suggest some advantages of genetically modified plants in agriculture.
Answer:

• Made crops more tolerant to abiotic stress
• Reduced the use of chemical pesticides
• Reduced post harvest loss
• Increased mineral usage efficiency

Plus Two Botany Biotechnology and its Applications Three Mark Questions and Answers

Question 1.
Polymerase Chain Reaction (PCR) and Enzyme-Linked Immuno – Sorbent Assay (ELISA) are some of the techniques that serve the purpose of early Diagnosis of disease like AIDS.

1. Write the scientific basis of this statement.
2. Write the name of pathogen causing AIDS.

Answer:
1. PCR – By amplification of the DNA of virus or bacteria present in the patient helps to identify even the concentration of pathogen is very low in the body of the patient. A single stranded DNA or RNA is tagged with a radio active molecule (probe) is allow to hybridized to its complementary DNA in clone of cells followed by detection using auto radiography .

Thus the mutated gene can be detected as it will not hybridize with the probe. ELISA – Enzyme linked immune sorbent assay is based on the principle of antigen antibody reaction. Infection by pathogen can be detected by the presence of antigen or by detecting antibodies synthesized against the pathogen.

2. HIV-human immuno deficiency virus.

Question 2.
For effective treatment of a disease early diagnosis and understanding its patho physiology is very important. Mention the 3 techniques which are used for the purpose of early diagnosis.
Answer:
PCR-By amplification of the DNA of vims or bacteria present in the patient helps to identify even the concentration of pathogen is very low in the body of the patient.

A single stranded DNA or RNA is tagged with a radio active molecule (probe) is allow to hybridized to its complementary DNA in clone of cells followed by detection using autoradiography. Thus the mutated gene can be detected as it will not hybridize with the probe.

ELISA – Enzyme linked immuno- sorbent assay is based on the principle of antigen-antibody reaction. Infection by pathogen is an antigen it can be detected by the presence of antibodies synthesized against it.

Question 3.
List out the milestones achieved in medicine by the introduction of recombinant DNA technique, citing examples.
Answer:
Recombinant DNA technology have made immense impact in the field of medicine both in diagnosis and therapeutics. Human insulin is produced by E.Coli which is engineered to produce A and B chains of polypeptide.

Gene therapy is curing of disease by delivery of a normal gene into the individual even at the embryo stage. Gene therapy is used to cure Adenosine deaminase deficiency.

Moleculardiagnosis involves PCR (Polymerase chain reaction)and ELISA. In polymerase chain reaction, the genes are amplified it helps to detect viral infection prior to the appearance of symptoms.

Question 4.
Animals that have their DNA manipulated and express foreign gene are called transgenic animals. Write any four characteristics of transgenic animals.
Answer:
1. Transgenic animal can be specifically designed to allow the study of the mechanism of gene expression, its regulation & how they effect the normal function & development.

2. It is also used to study the biological effects of certain gene product & also the biological role of these products in the body.

3. Transgenic animals serve as models for human disease. So that investigation of new treatment for disease is made possible.
Example : Alzheimer’s, cancer, Cystic, fibrosis, etc.

4. Transgenic animal are used produce medicine it is used to treat diseases like Emphysema. The transgenic cow rosie produced human protein enriched milk (alpha- lactalbumin).

5. They are also used for testing the safety of vaccines like polio. It is also used for testing toxicity of drugs.

Question 5.
ADA deficiency is permanently cured by gene therapy.

1. Expand ADA.
2. Write its normal function in human body.
3. If gene for ADA is deleted the person will become susceptible to attack of pathogens and die of ordinary diseases. By analysing the given statement can you explain the role of ADA.
4. Can you suggest alternative methods for curing the same disease?

Answer:

1. Adenosine deaminase
2. It is a crucial enzyme for the immune system to function.
3. The patients have non-functioning T- Lymphocytes. So they cannot produce immune responses against invading pathogens.
4. Yes. Gene therapy is used for permanent curing of ADA deficiency.

There are two methods for treatment of ADA deficiency.

• by bone-marrow transplantation
• and by enzyme replacement therapy.

Question 6.
Expand

1. ELISA
2. GEAC
3. RNA i

Answer:

1. Enzyme-Linked Immuno Sorbent Assay
2. Genetic Engineering Approval Committee
3. RNA interference

Question 7.
In 1990 first test of human gene therapy was performed in 4-year-old girl ‘De Silva’ with adenosine deaminase deficiency.

1. Name the method used to cure the disease
2. Explain the procedure of r DNA technology used to recover adenosine deaminase deficiency
3. Which is the best cure for this disease?

Answer:
1. Gene therapy.

2. Lymphocytes are taken from patient’s blood it is grown invitro culture. By using retroviral vector functional ADA cDNA (from WBC of normal person) is introduced into vitro cultured lymphocytes These genetically engineered lymphocytes (corrected functional lymphocytes) are reinjected into the patients.

3. If the ADA producing genes are introduced into cells at early embryonic stage it could be a permanent cure.

Question 8.
You have developed a GM plant.

1. Which govt, organization will you approach to obtain clearence for its mass production?
2. Is such a body is necessary?
3. Give two reasons.

Answer:

1. GEAC-genetic engineering approval committee
2. Yes
3. It will make decisions regarding the validity of GM research & the safety of introducing GM organism for public services. It also deals with the patenting problems.

Question 9.
In Tobacco plants pest resistance is achieved by a special technique.

1. Name the technique
2. Which is the pest killed by this way?
3. Explain the method.

Answer:

1. RNA interference
2. Meloidegyne incognitia(nematode)
3. It is the silencing of mRNA done by a double-stranded RNA (dsRNA).

In this technique the pest resistant gene (cDNA) is transferred into host plant by using agrobacterium vector, which become double stranded and silences the mRNA of the pest from expressing inside the host. Thus the plant become resistant to the pest which cannot survive inside the host.

Question 10.
Bacillus thuringienesis is a Bacteria, which produce a toxic insecticidal protein.

1. Write down the significance of this bacteria in GMO.
2. Insecticidal protein is not harmful to the body of man. Why?

Answer:
1. Bacillus thurungenesis produce a protein Cry protein coded by the cry gene. This protein kill certain insects like lepidopterarns (tobaccobud worm), boll worms, dipterans like mosquitoes.

These genes are isolated from Bacillus thuringenesis and incorporated into several crop plants like cotton. There are specific cry gene for specific toxin and each toxin controls or destroys specific insect.

2. Protein crystals solubilise only in the presence of alkaline pH but stomach of human body contains acidic pH .So it doesn’t make any harmful effect in humans.

Question 11.
Give example of vaccine safety in respect to transgenic animals.
Answer:
Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of polio vaccine.

Question 12.
Animals that have their DNA manipulated and express foreign gene are called transgenic animals. Write down the three significance of transgenic animals used as models.
Answer:
1. Normal physiology and development:
To study of how genes are regulated, and how they affect the normal functions of the body and its development.

2. Study of disease:
How genes contribute to the development of disease.

3. Chemical and vaccine safety testing:
Transgenic animals carry genes that sensitive to toxic substances and the effects can be studied.

Question 13.
An early diagonosis of disease can be detected by modern techniques.

1. How can PCR detect very low amounts of DNA?
2. What is Probe?

Answer:

1. PCR is a Polymerase Chain Reaction, which amplifies low amount of DNA making multiple copies of which ft helps in the diagnosis of low amount of DNA.
2. It is the single stranded radioactively labelled DNA.

Question 14.
Insecticidal protein crystal are not a solubilized in acidic PH but it is solubilized and become active in alkaline pH. Name the organism possess alkaline PH in their gut?
Answer:
Insects- lepidopterans, coleopterans and depterans.

Question 15.
RNA interference technology is used to prevent transcription process of protein synthesis. Justify the given statement
Answer:
It is used t0 silence the m RNA of nematode by using double-stranded RNA. Here nematode specific genes are introduced into host plant by using agrobacterium vectors, that produce double-stranded RNA and initiated RNA silencing process.

Question 16.
Earlier ADA deficiency can be cured by enzyme replacement therapy or bone marrow transplantation. Write down the procedure used in r-DNA technology to cure the disease.
Answer:
Lymphocytes taken from patients blood it is cultured outside, into this functional ADA cDNA are introduced, then this Lymphocytes are taken back into the patient’s blood. For permanent cure, functional ADA cDNA are introduced into embryonic stage.

Question 17.
Our country is very rich in biodiversity and traditional knowledge. So we have faced many problems related to biopiracy.

1. What is biopiracy?
2. Give two examples of biopirated plants.
3. How can we control biopiracy?

Answer:

1. Un authorized use of bioresources and traditional knowledge without compensatory payment
2. Basmati rice, turmeric.
3. By developing laws and regulations or through patent Bill.

Question 18.
Transgenic animals are those animals whose DNA is manipulated and has an extra or foreign gene to possess and express.

1. How can transgenic animals help in testing for vaccine safety.
2. Name the enzyme produced by transgenic animal which is used against emphysema.
3. For which diseases transgenic models exist?
4. Name the first transgenic cow. Write its significance.

Answer:

1. Transgenic animals like mice are developed for testing of vaccine before they are used on humans.
2. An enzyme a-1-antitrypsin can be obtained from a transgenic animal which is used against emphysema.
3. Transgenic model exist for cancer, cystic fibrosis, Alzheimer’s diseases, etc.
4. Rosie is the first transgenic cow, was produced human protein enriched milk. The milk contains alpha-lactalbumin in the amount of 2.4 gram per litre and is more nutritionally balanced for

Plus Two Botany Biotechnology and its Applications NCERT Questions and Answers

Question 1.
Can you suggest a method to remove oil (hydro carbon) from seeds based on your understanding of rDNA technology and chemistry of oil?
Answer:
Oil is lipid synthesized by the condensation of one molecule of glycerol with three molecules of fatty acids. Thus, the oil from the seeds can be removed by preventing the synthesis of either glycerol or the enzyme lipase which catalyses the synthesis of oil. It can be achieved by knocking out the genes coding for the enzyme required for the synthesis of glycerol.

Question 2.
What are cry proteins? Name an organism that produce it. How has man exploited this protein to his benefit?
Answer:

1. Cry proteins refer to the protein crystals contain¬ing atoxic insecticide.
2. It is produced by soil bacterium, Bacillus thuringiensis.
3. The genes encoding cry proteins called Bt toxin genes were isolated from B. thuringiensis and incorporated into several crop plants such as Bt cotton, Bt corn, etc, to provide resistance against insect pests.

Question 3.
Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?
Answer:
For making any oral drug or nutritional supplement the action of digestive enzymes has to be taken into account. Most of the antibiotic and vitamin supplements are made in capsule forms to prevent action of HCI in stomach.

For protein preparation the major source is groundnut shells. The protein extracted from the source is predigested so as to make them absorbable by the digestive system.

Question 4.
Find out from internet, what is golden rice?
Answer:
Golden ric is genetically modified and contain Carotene, which is a precursor of Vitamin A.

Question 5.
Does our blood have proteases and nucleases?
Answer:
No.

Question 6.
Compare and contrast the advantages and disadvantages of production of genetically modified crops.
Answer:
Advantage of GM Crops:

1. Genetic modification has made crops more tolerant to abiotic stresses (cold, drought, heat, salt)
2. Viral resistance can be introduced.
3. Over ripening losses can be reduced eg: Flavr Savr tomato
4. Enhanced nutritional value of food eg: Golden rice. Reduced reliance on chemical pesticides.

Disadvantages of GM Crops:

1. Transgenes in crop plants can endanger native species. For example, the gene for Bt toxin expressed in pollen might end natural pollinators like honey bees.
2. Weeds also become resistant.
3. Products of transgene may be allergic or toxic.
4. They cause damage to the natural environment.

Question 7.
Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because:
(a) Bacteria are resistant to strain
(b) Toxin is immature
(c) Toxin is inactive
(d) Bacteria encloses toxin a special sac.
Answer:
c) Toxin is inactive
Because Bt toxin is present in the form of protoxin in Bacillus bacterium.

Question 8.
Why does this toxin not kill the Bacillus? How it affects insect?
Answer:
The Bt toxin protein exist as inactive protoxins but once an insect ingest the inactive toxin, it is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals.

The activated toxin binds to the surface of midgut epithelial cells and create pores that cause cell swell¬ing and lysis and eventually cause death of the insect.

Plus Two Botany Biotechnology and its Applications Multiple Choice Questions and Answers

Question 1.
Which of these is used as vector in gene therapy for SCID?
(a) Arbovirus
(b) Retrovirus
(c) Enterovirus
(d) Parvovirus
Answer:
(b) Retrovirus

Question 2.
Find the incorrect statement.
(a) Gene therapy is a genetic engineering technique used to treat disease at molecular level by replacing defective genes with normal genes.
(b) Calcitonin is a medically useful recombinant product in the treatment of infertility
(c) Bt toxin is biodegradable insecticide obtained from Bacillus
(d) Trichoderma sp.is a biocontrol agent for fungal diseases of plants
Answer:
(b) Calcitonin is a medically useful recombinant product in the treatment of infertility

Question 3.
The technique of DNA fingerprinting was initially developed by
(a) lanWilmut
(b) HarGobindKhurana
(c) Jacque Monod
(d) Alex Jeffreys
Answer:
(d) Alex Jeffreys

Question 4.
Plasmids are suitable vectors for gene cloning because
(a) these are small circular DNA molecules, which can integrate with host chromosomal DNA
(b) these are small circular DNA molecules with their own replication origin site
(c) these can shuttle between prokaryotic and eukaryotic cells
(d) these often carry antibiotic resistance genes
Answer:
(b) these are small circular DNA molecules with their own replication origin site

Question 5.
Cry II Ab and Cry I Ab Produce toxins that control
(a) cotton bollworms and corn borer respectively
(b) corn borer and cotton bollworms respectively
(c) nematodes and tobacco budworms respectively
(d) corn borer and tobacco budworms respectively
Answer:
(a) cotton bollworms and corn borer respectively

Question 6.
Golden rice was created by transforming rice with two beta-carotene biosynthesis genes, namely.
(a) Psy and Cry 1 genes
(b) LCY-e
(c) CHY-1
(d) CHY-2
Answer:
(a) Psy and Cry 1 genes

Question 7.
Main objective of production / use herbicide resistant GM crops is to
(a) eliminate weeds from the field without the use of manual labour
(b) eliminate weeds from the field without the use of herbicides
(c) encourage eco-friendly herbicides
(d) reduce herbicides accumulation in food articles for health safety
Answer:
(d) reduce herbicides accumulation in food articles for health safety

Question 8.
Biopiracy is related to which of the following?
(a) traditional knowledge
(b) Biomolecules and regarding bioresources
(c) Bioresources
(d) All of the above
Answer:
(c) Bioresources

Question 9.
Genetic engineering has been successfully used for producing
(a) transgenic mice for testing safety of polio vaccine before use in humans
(b) transgenic models for studying new treatments for certain cardiac diseases
(c) transgenic cow-Rosie, which produces high-fat milk for making ghee
(d) animals like bulls for farm work as they have superpower
Answer:
(a) transgenic mice for testing safety of polio vaccine before use in humans

Question 10.
The genetic defect-Adenosine Deaminase deficiency may be cured permanently by
(a) periodic infusion of genetically engineered lymphocytes having functional ADA C-DNA
(b) administering adenosine deaminase activators
(c) introducing bone marrow cells producing ADA into cells at early embrayonic stages
(d) enzyme replacement therapy
Answer:
(c) introducing bone marrow cells producing ADA into cells at early embrayonic stages

Question 11.
RNA interference method involves
(a) Silencing of a specific in RNA due to a complementary ssRNA
(b) Silencing of a specific tRNA due to a complementary dsRNA
(c) Silencing of a specific mRNA due to a complementary ssRNA
(d) Silencing of a specific mRNA due to a complementary dsRNA
Answer:
(d) Silencing of a specific mRNA due to a complementary dsRNA

Question 12.
The nematods that infects the roots of tobacco plants and causes a great reduction in yield is
(a) Meloidegyneincognitia
(b) Bacillus thuringiensis
(c) Agrobacterium tumifaciens
(d) Rhizobium meliloti
Answer:
(a) Meloidegyneincognitia

Question 13.
RNAi takes place in all eukaryotic organisms as a method of
(a) Cellular defense
(b) DNA proof reading
(c) Transcription
(d) Translation
Answer:
(a) Cellular defense

Question 14.
The main challenge for production of insulin peptide using rDNA technique was
(a) Getting normal insulin gene
(b) Getting insulin assembled into a mature form
(c) Getting insulin chains formed from bacteria
(d) Getting insulin assembled into proinsulin
Answer:
(b) Getting insulin assembled into a mature form

Question 15.
Bacillus thuriengiensis(Bt) strains have been used as biological control for plants, its application is famous in
(a) cotton
(b) tomatoes
(c) brinjal
(d) both a and c
Answer:
(d) both a and c

Question 16.
Cry endotoxins obtained from Bacillus thuriengensis are effective against
(a) nematode
(b) bollworms
(c) mosquitoes
(d) flies
Answer:
(b) bollworms

Question 17.
Transgenic animal has
(a) foreign DNA
(b) recipient DNA
(c) both a& b
(d) none of the above
Answer:
(c) both a& b

Question 18.
Genetically engineered cotton plant shows resistance to boll worm insects, but their source of desired gene not induce any adverse effect in bacteria because
(a) cell wall is thick and tough
(b) cell wall is made up of special type of lipids
(c) cytosol does not contain alkaline solution
(d) both b and c.
Answer:
(c) cytosol does not contain alkaline solution

Question 19.
Humulin is prouced in large scale for the specific purpose by
(a) Tissue culture
(b) organ culture
(c) Bio-reactor
(d) none of the above
Answer:
(c) Bio-reactor

Question 20.
Transgenic food crop which help in solving the problem of night blindness in developing countries is
(a) Bt cotton
(b) golden rice
(c) flvrsavr tomatoes
(d) starlink maize
Answer:
(b) golden rice

Question 21.
In the technique RNA interferance the silencing is done to terminate the function of
(a) hn RNA
(b) m RNA
(c) sn RNA
(d) all the above
Answer:
(b) m RNA

Question 22.
If the gene function is disrupted, it corrected by the technique called as
(a) gene slicing
(b) gene splicing
(c) gene therapy
(d) all the above
Answer:
(c) gene therapy

Question 23.
The gene product provides good result as the protein contained in the breast milk is
(a) albumin
(b) alpha lactalbumin
(c) globulin
(d) glutelin
Answer:
(b) alpha lactalbumin

Question 24.
The processed genetically engineered insulin contains
(a) A polypeptide chain
(b) B polypeptide chain
(c) c peptide
(d) both a and b
Answer:
(d) both a and b

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Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 4 Biotechnology Principles and Processes

Plus Two Botany Biotechnology: Principles and Processes One Mark Questions and Answers

Question 1.
Ti plasmids used in genetic engineering is obtained from
(a) Bacillus thuringiensis
(b) Agrobacterium tumefaciens
(c) Pseudomonas tumefaciens
(d) Bacillus subtilis
Answer:
(b) Agrobacterium tumefaciens

Question 2.
Which one is regarded as a molecular scissor in biotechnology?
(a) Reverse transcriptase
(b) Restriction endonuclease
(c) Taq polymerase
(d) Topoisomerase
Answer:
(b) Restriction endonuclease

Question 3.
Name the stain used to identify DNA bands in gel electrophoresis
Answer:
Ethidium Bromide

Question 4.
In rDNA technology the alein DNA and cloning vector are a cut by same Restriction endonuclease enzyme. Give reason.
Answer:
The same restriction enzyme must be used cut the alien and foreign DNA forgetting sticky ends.

Question 5.
Name the most common technique is used to transfer DNA into plants.
Answer:
Biolistics or gene gun

Question 6.
The plasmid of Agrobacterium is
(a) Ti plasmid
(b) F1 plasmid
(c) T plasmid
(d) Col E1
Answer:
(a)Ti plasmid

Question 7.
Which of the following is not a restriction endonuclease?
(a) EcoRI
(b) Hind III
(c) pst I
(d) DNAse I
Answer:
(d) DNAse I

Question 8.
The desired DNA can be amplified to 1 billion copies through an important technique. Name it.
Answer:
Polymerace Chain Reaction

Question 9.
Restriction in Restriction enzyme refers to:
(a) Cleaving of phosphodiester bond in DNA by the enzyme
(b) Cutting of DNA at specific position only
(c) Prevention of the multiplication of bacteriophage in bacteria
(d) All of the above
Answer:
(c) Prevention of the multiplication of bacteriophage in bacteria

Question 10.
In PCR technique, nucleotides add one by one on template strand with the help of polymerace enzyme. From which organism it is isolated.
Answer:
Thermus aquaticus

Question 11.
A recombinant DNA molecule can be produced in the absence of the folloiwng:
(a) Resriction endonuclease
(b) DNA ligase
(c) DNA fragments
(d) E.coli
Answer:
(d) E.coli

Question 12.
In agarose gel electrophoresis, DNA molecules are separated on the basis of their:
(a) Charge only
(b) Size only
(c) Charge to size ratio
(d) All of the above
Answer:
(b) Size only

Question 13.
Which of the following bacteria is not a source of restriction endonuclease?
(a) Haemophilus influenzae
(b) Esherichia coli
(c) Agrobacterium tumefaciens
(d) Bacillius amyloli
Answer:
(a) Haemophilus influenzae

Question 14.
Which of the following steps are catalysed by Taq polymerase in a PCR reaction?
(a) Denaturation of template DNA
(b) Annealing of primers to template DNA
(c) Extenstion of primer end on the template DNA
(d) All of the above.
Answer:
(c) Extenstion of primer end on the template DNA

Question 15.
An enzyme catalysing the removal of nucleotides from the ends of DNA is:
(a) endonuclease
(b) exonuclease
(c) DNA ligase
(d) Hind-ll
Answer:
(b) exonuclease

Question 16.
Polymerase Chain Reaction helps in
(a) DNA synthesis
(b) DNA amplification
(c) Protein synthesis
(d) Aminoacid synthesis
Answer:
DNA synthesis

Question 17.
Starting from double stranded DNA suggest a strategy for obtaining large amounts of pure single stranded DNA for sequencing purpose.
Answer:
PCR (POLYMERASE CHAIN REACTION)

Question 18.
The cutting of DNA at specific locations became possible with the discovery of ensymes called ‘molecular scissors’. Identify this enzyme.
Answer:
Restriction enzymes/Restriction Endonucleases

Question 19.
Which among the following is the first discovered Restriction Endonuclease?
(a) Hindi I
(b) Hindi II
(c) EcoR I
(d) EcoR II
Answer:
(b) Hind II

Question 20.
Observe the following illustration and find out the enzymes which are denoted as A and B.
Answer:

1. Restriction endonucleases
2. DNAIigases

Question 21.
Write the technique used for the separation of DNA fragments.
Answer:
Gel Electrophoresis

Question 22.
Final step of gel electrophoresis of DNA molecules from the gel. What is this process called?
Answer:
Elution

Question 23.
One of the given options is not related to PCR. Find it.
(a) Denaturation
(b) Spooling
(c) Extension
(d) Annealing
Answer:
Spooling

Question 24.
Which among the following is not a gene transfer method?
(a) Microinjection
(b) Disarmed pathogen vectors
(c) Gene gun
(d) Elution
Answer:
(d) Elution

Question 25.
Cloning vector suitable for gene transfer in plants is
(a) Ti plasmid
(b) Bacteriophages
(c) Viruses
(d) Transposons
Answer:
(a) Ti Plasmid

Question 26.
Which among the following are the selectable markers of PBR-322.
(a) amp^R, kan^R
(b) tet^R, kan^R
(c) ampR, tetR
(d) chl^R, tet^R
Answer:
ampR, tetR

Question 27.
Restriction Endonucleases cut DNA at specific locations by breaking_______
(a) Sugar-phosphate bonds
(b) Sugar-Nitrogen base bonds
(c) Hydrogen bonds
(d) Disulphide bonds
Answer:
Sugar-phosphate bond

Question 28.
Downstream processing is the final step in the process of recombinant DNA technology. What do you understand by “down stream processing”?
Answer:
Separation and purification of gene product.

Question 29.
Ti plasmid is a suitable cloning vector for plants. It is the plasmid of a bacterium called_______.
Answer:
Agrobacterium tumifaciens.

Plus Two Botany Biotechnology: Principles and Processes Two Mark Questions and Answers

Question 1.
Elution is a major step of electrophoresis.

1. Explain the process.
2. Give the importance of UV light

Answer:

1. Separated bands of DNA are cut from Agarose gel piece and extracted out.
2. Under UV light DNA bands are observed as orange colour.

Question 2.
Genetic engineering is the gene manipulation technique that helps to create new organism with desired genetic make up

1. Give the contribution of Stanley cohen and Herbert Boyer in genetic engineering.
2. Name the enzyme used to cut DNA strand?

Answer:

1. Herbert Boyer and Stanley cohen constructed first recombinant DNA by linking a gene encoding antibiotic resistance with a native plasmid of Salmonella typhimurium in 1972.
2. Restriction endonuclease

Question 3.
Mosquitoes are considered as vectors which transfer the malarial parasite into human body. Plasmids are considered as Vectors in biotechnology’. Justify.
Answer:
Vectors are agents which transfers materials from one organism to another. Plasmids are extra chromosomal DNA seen in bacteria which have the ability for independent replication.

In the field of Biotechnology plasmids are used as vectors as they replicate rapidly after integrating a foreign DNA. Thus, through the plasmid the alien gene can be introduced into another organism.

Question 4.
Eco R I is the restriction endonuclease enzyme obtained from E.coli bacteria that helps them to restrict the growth of virus. What are the criteria for naming endonucleases.
Answer:
EcoRI comes from the name of bacterium Escherechia coli Ry 13. E represents the genus, co represents species, ‘R’ is derived from the name of strain and I is the order in which the enzyme is isolated.

Question 5.
Separation and isolation of DNA fragments can be done by a technique known as gel electrophoresis

1. What is the procedure used separate DNA fragements?
2. Name the organism from which agarose gel is isolated

Answer:
1. Negatively changed DNA fragments are separated by forcing them to move towards the anode under an electric field through agarose matrix.

The DNA fragments separate according to their size in agarose gel. So the smaller the fragment size moves farther. Then it is cut out from the agarose gel by elution.

2. Seaweeds.

Question 6.
PCR is meant for making the multiples copies of the gene of interest.

1. Give the major step involved in PCR.
2. Name the thermostable DNA polymerase enzyme is used in this technique. Why?

Answer:
1. The major step involved in PCR:

• Denaturation – It involves the separation of DNA strands
• Annealing – The double strands are synthesised from free nucleotides by the action of DNA polymerase.
• Extension – The length of the strands are increased as a result of addition of more and more nucleotides. Thus DNA amplified up to 1 billion copies.

2. Taq polymarase
PCR cylinderworks at high temperature. Hence thermostable enzyme is used.

Question 7.
In r DNA technology recombinant DNA is directly injected into the plant cell

1. Name the technique used
2. What you meant by competent host?

Answer:

1. Biolispics or Gene gun.
2. This is done by treating them with calcium ions and incubating the cells and recombinant DNA on ice, followed by placing them at 42°C. Then putting them back on ice. This helps the bacteria to take up the recombinant DNA.

Question 8.
If RNA use, protease, cellulase etc. are not used in the isolation of genetic materials.

1. Find out the difficulties arise during the process of rDNA technology.
2. What is spooling?

Answer:

1. If the above said enzymes are not used, it is difficult to get DNA in pure form for foreign gene isolation.
2. Fine thread of DNA separated out from chilled alcohol.

Question 9.
How is the action of Exonuclease different from that of endonuclease?
Answer:
Exonuclease removes the nucleotides from the ends of DNA molecules while endonuclease takes cut at specific position within a DNA molecule.

Question 10.
Spooling is one of the important method used in r DNA technology.

1. Name the medium in which DNA appear as fine threads.
2. What is the aim of using lysozyme in the isolation of genetic material?

Answer:

1. Chilled alcohol
2. It helps to remove the cell wall of bacteria

Question 11.
Sticky ends are unpaired strands of DNA get by using restriction endonuclease enzyme.
Do you agree?.Give reason
Answer:
Yes. The same restriction enzyme is used to cut both vector DNA and foreign DNA, get sticky ends that facilitate the action of DNA ligase.

Question 12.
In biotechnology lab Ramu interested in constructing r DNA, for this he used tools of r DNA technology.

1. What happen if DNA polymerase enzyme is not used?
2. Name the sequence of DNA subjected to the action of restriction enzyme

Answer:

1. Addition of nucleotides not take place
2. Palindromic sequence

Question 13.
3′ end of template strand is very important in polymerase chain reaction

1. Name the complementary strand that attaches template sequence of 3′ end
2. Find out the type of nucleotides supplied in this technique

Answer:

1. Primer
2. dCTP, d ATP, d GTP, d TTP

Question 14.
In r DNA technology recombinant DNA is directly injected into the plant cell

1. Name the technique used
2. Can you explain two other methods for gene transfer?

Answer:
1. Microinjection.

2. Methods for gene transfer:

a. The bacterium is treated with divalent cation such as calcium which makes the bacterial cell competent to take up DNA (the pores bacterial cell wail is widened).

The recombinant DNA is forced in to the cell by incubating cells with recombined DNA on ice followed by heat shock (42YC) and then back on ice. This helps the bacteria to take up recombined DNA.

b. High velocity micro particles of gold or tungsten is coated with DNA & bombarded into the cell. This method is called biolistics or gene gun.

Question 15.
A researcher in biotechnology is in need to produce insulin in large amounts as part of his study.

1. Which instrument will he select for the purpose?
2. What are the facilities in the instrument?

Answer:
1. Bioreactor.

2. A bioreactor commonly use a stirring type. It consists of cylindrical tank with a stirrer which facilitate mixing of the content of the reactor. It also facilitate oxygen availability.

An agitator system, an oxygen delivery system, temperature control system, pH control system are present in a bioreactor. Small volumes of the products are removed through sampling ports periodically.

Question 16.
In r DNA technology amplification of genetic material is important, In such a device

1. Thermostable enzyme must be used why?
2. Name it.

Answer:

1. The working of programmed cylinder for PCR requires high temperature . Hence thermostable DNA polymerase is used
2. Taq polymerase

Question 17.
It is difficult to use other bacteria instead of Agrobacterium for the transfer of desired gene into plants. Do you agree? Give reasons.
Answer:
Yes. Agrobacterium possess Ti plasmid , it has the ability to transfer gene into dicot plants through infection. Hence it is widely used in gene transfer.

Question 18.
When chromogenic substrate is added to the medium containing bacterial colonies are subjected to insertional inactivation, some appears as blue coloured and others as white coloured colonies. Give reasons.
Answer:
The colonies appears as blue coloured does not possess for eigengene they are called non-recombinants while the colonies of white coloured have foreign gene insert, they are called as recombinants.

The production of blue colour is due to the reaction between beta-galactosidase enzyme and chromogenic substrate while the white coloured colonies have no enzyme for reaction with substrate.

Question 19.
Even though salmonella, Ecoli etc. contains plasmids PBR 322 is widely used in genetic engineering. Why?
Answer:
The plasmid PBR 322 is artificial cloning vector, it possess several features such as origin of replication, selectable marker, cloning sites etc. Some features of artificial cloning vector is not found in natural plasmid. Hence PBR 322 is widely used in genetic engineering.

Question 20.
What you meant by selectable marker? Give 2 examples.
Answer:
The selectable marker is antibiotic resistant gene. Examples are ampicilin resistant and tetracycline resistant gene.

Question 21.
If RNA ase, protease, cellulaseetc are not used in the isolation of genetic materials. Find out the difficulties arise during the process of rDNA technology.
Answer:
If the above said enzymes are not used, it is difficult to get DNA in pure form for foreign gene isolation.

Question 22.
DNA is a hydrophilic molecule, so it can’t pass through the cell membrane. How can DNA inserted into a Bacterial cell?
Answer:
Bacterial cells must have to be competent to take up DNA. This is done by treating them with calcium ions and incubating the cells and recombinant DNA on ice, followed by placing them at 42_oC Then putting them back on ice. This helps the bacteria to take up the recombinant DNA.

Question 23.
State principle underlying gel electrophoresis and mention two applications of this technique in biotechnology.
Answer:
The molecular separation in gel electrophoresis are based on gel filtration as well as electrophoretic mobilities of the molecules being separated. It is among the most powerful and yet conveniently used method of macro molecular separation.

Question 24.
How has Agrobacterium tumifaciens has been suitably modified to act as cloning vector?
Answer:
Genes are transferred from bacterium or virus to eukaryotic cells and these genes force the transformed cell to works at their will eg: Agrobacterium-mediated gene transfer.

Question 25.
How is the action of Exonuclease different from that of endonuclease?
Answer:
Exonuclease removes the nucleotides from the ends of DNA molecules while endonuclease takes cut at specific position within a DNA molecule.

Question 26.
According to the size and charge of DNA sequence that move in an agarose gel,the smaller fragment is selected for cloning

1. Name the technique is used to’separate digested and undigested fragments
2. Which is the method used to get pure DNA fragment from agarose gel

Answer:

1. Gel electroforesis
2. Elusion

Question 27.
Why is the enzyme cellulose used for isolating genetic material from plant cells but not for animal cells?
Answer:
Due to the presence of cell wall in plants cellulose is used, whereas the animal cell lacks cell wall.

Question 28.
Following is the sequence of nucleotide in two strands of DNA .observe the strands and answer the preceding questions
5’ GAATTC 3’
3’ CTTAAG 5’

1. Name the special term used for such an arrangement of nucleotide
2. Name the special type of enzyme which work/function at this specific points
3. Name the enzyme that cut DNA between GA sequence.
4. Name the single strands produced after the action of the enzyme.

Answer:

1. Palindromes
2. Restriction endonucleases
3. E co Rl
4. Sticky strands

Question 29.
DNA cutting enzymes are mainly isolated from prokaryotes

1. Do eukaryotic cells have restriction endonucleases?
2. Justify your answer.

Answer:

1. No.
2. They do not have restriction endonucleases. The eukaryotic cells have some other means of defence against viral infection, i.e., immune system.

Question 30.
Give an example of micro organisms that have transforming ability.
Answer:
A bacterium Agrobacterium tumefactions has T- DNA in its Ti-plasmid which is able to transform normal plant cells to tumour cell and cause crow gall tumours in plants.

Question 31.
‘One of the limitations of traditional hybridization is that it leads to inclusion and multiplication of undesirable genes along with the desired genes’. How does genetic engineering help to overcome these limitations?
Answer:
In this method desirable genes/alien gene can be cut and incorporated into plasmid and thus recombinant DNA is prepared . Then introduced into the target organism.

Question 32.
In-gel electrophoresis, we cannot see pure DNA fragments in visible light and without staining. Explain how is it possible to visualize the DNA fragments?
Answer:
Staining the DNA with Ethidium bromide, followed by exposure to UV radiation.

Question 33.
Figure given below is an important technique used in genetic engineering.

1. Identify the technique.
2. Find out the aim technique.

Answer:

1. Gel electrophoresis
2. Separation of DNA fragments

Question 34.
Match the following columns A and B suitably

Answer:

Question 35.
Given below is the diagram of a cloning vector.

1. Identify the vector
2. What do amp^R and tet^R stand for?

Answer:

1. pBR 322
2. amp^R – ampicillin resistant gene, tet^R tetracyclin resistant gene.

Question 36.
Each restriction endonuclease recognizes a specific palindromic nucleotide sequence in the DNA.

1. What is a palindrome?
2. Give one example.

Answer:

1. Palindrome is a sequence of base pairs that reads same on two strands of DNA molecule
2. 5′ GAATTC 3′
3. 3′ CTTAAG 5′

Question 37.
Given below are some enzymes used for the release of DNA molecules from different types of cells. Lysozyme, chitinase, cellulose. Arrange them suitably in the columns provided below.

Answer:

Question 38.
Select markers help us in identifying and eliminating non transformed cells during gene cloning. Explain how the gene for beta-galactosidase enzyme works as a selectable marker?
Answer:
When recombinant DNA inserted within the coding sequence of the enzyme beta-galactosidase, the gene for the enzyme production is removed, after this colonies are transferred into growing medium containing chromogenic substrate, non-transformed colonies give blue colour but transformed colonies not give any colour due to insertional inactivation.

Question 39.
In order to force bacteria to take up the plasmid, the bacterial cells must first be made ‘competent’ to take up DNA. Suggest a method to make bacterial cell competent to receive DNA.
Answer:
At first, treat the cell with divalent cation like calcium, which increases the efficiency with which DNA enters the bacterium through pores in the cell wall. Then incubate of cell with rDNA on ice and placing them briefly at 42° C and then putting back to ice.

Question 40.
Multiple copies of the gene of interest is synthesized in vitro using DNA polymerase enzyme.

1. Which are the three steps of the above process?
2. Find out the DNA polymerase enzyme used here.

Answer:

1. Three steps of the above process:

• Denaturation
• Annealing
• Extension

2. Thermostable DNA polymerase/Taq polymerase.

Question 41.
Bioreactors help for the large scale production of recombinant proteins.

1. Which are the two commonly used bioreactors?
2. What is the purpose of stirring mechanism in a bioreactor?

Answer:

1. Simple stirred tank bioreactor
2. Sparged stirred tank bioreactor

The stirrer facilitates mixing of content and o₂ availability.

Question 42.
Given below is the diagram of a cloning vector. Observe the diagram and answer the following questions.

1. Name the bacterium from which this vector is made?
2. What are the significances of ‘ori’ and ‘rop’ denoted in the picture?

Answer:

1. Ecoli
2. “ori”-origin of replication it is the point from which replication starts “rop”- codes for proteins involved in replication of plasmid.

Question 43.
Restriction Endonucleases are enzymes responsible for cutting of DNA molecule. Eco Rl is derived.

1. How the name Eco Rl is derived?
2. Write the palindromic sequence of Eco Rl.

Answer:
1. First letter from the genus and second two letters from the species name Letter ‘R’ is derived from the type of strain Roman number I indicates the order of discovery.

2. 5′ ………..GAATTC 3′
3’…………CTTAAG 5′

Plus Two Botany Biotechnology: Principles and Processes Three Mark Questions and Answers

Question 1.
Write any three uses of Gene cloning.
Answer:

1. Genes of interest can be inserted into animals, so as to produce better farm animals.
2. Desired proteins like insulin, hormones, interferons, vitamins can be manufactured in bacteria on an industrial basis.
3. Recombinant vaccines, improved antibiotics can be produced by gene cloning.

Question 2.

1. 1. Identify the process.
   2. Identify the enzymes involved in steps (ii) and (iii)

1. Write the base sequences recognised by EcoRI

Answer:
1. Recombinant DNA technology.

2. enzymes involved in steps:

• Restriction Endonuclease
• Ligase enzyme

3. sequences recognised by EcoRI:

• GAATTC
• CTTAAG

Question 3.
Vehicles which are used to transfer a gene from one cell to another is called a cloning vector. PBR 322 is a widely used cloning vector.

1. Name 2 important features that a cloning vector should possess.
2. What is the importance of Ori?

Answer:

1. Origin of replication Selectable marker
2. Origin of replication the point from which replication begins.

Question 4.
Stanley cohen and Hebert Boyer constructed r DNA by using plasmid and antibiotic-resistant gene.

1. Name the slicing and splicing enzyme used.
2. What is the significance of slicing enzyme in rDNA technology?

Answer:
1. Slicing enzyme – Restriction endonuclease Splicing enzyme-DNA ligase

2. significance of slicing enzyme in rDNA technology:

• It is used to cut within DNA sequence.
• Same restriction enzyme is used to cut both vector DNA and foreign DNA.

Question 5.
Match the items in column A with the items of Column B.

Answer:

Question 6.
Following is the sequence of nucleotide in two strands of DNA. Observe the strands and answer the preceding questions
5’ GAATTC 3’
3’ CTTAAG 5’

1. Name the special term used for such an arrangement of nucleotide
2. Name the enzyme that cut DNA between GA sequence.
3. Name the single strands produced after the action of the enzyme.

Answer:

1. Palindromes
2. EcoRI
3. Sticky strands

Question 7.
Following are the various steps of recombinant DNA technology. Arrange them in correct sequential order.

i) Obtaining the foreign gene product
ii) Amplification of gene of interest using PCR
iii) Cutting of DNA at specific locations
iv) Downstream processing
v) Intsertion of recombinant DNA into the host cell/organism
vi) Isolation of genetic material
Answer:
vi) Isolation of genetic material
iii) Cutting of DNA at specific locations
ii) Amplification of gene of interest using PCR Insertion of recombinant DNA into the host cell organism
i) Obtaining the foreign gene product
iv) Downstream processing

Plus Two Botany Biotechnology: Principles and Processes NCERT Questions and Answers

Question 1.
From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?
Answer:
DNA molecules are bigger in molecular size as compared to molecular size of enzymes. It is because an enzyme (protein) is synthesized from the segment of DNA called gene.

Question 2.
What would be the molar concentration of human DNA in a human cell?
Answer:
In human being the concentration of DNA is 0.4%. It contains 6.6 × 10⁹ bp.

Question 3.
Besides better aeration and mixing properties, what other advantage do stirred tank bioreactors have over shake flasks?
Answer:
Shake flasks are used for growing microbes and mixing the desired materials on a small scale in the lab. But the large scale production of desired bio technological product requires large stirred tank bioreactors. Besides better aeration and mixing properties, the bioreactors have following advantages –

1. It has oxygen delivery system.
2. It has foam control, temperature and P^ control system.
3. Small volumes of culture can be withdrawn periodically.

Question 4.
Do eukaryotic cells have restriction endonucleases? Justify your answer.
Answer:
No. They do not have restriction endonucleases. The eukaryotic cells have some other means of defence against viral infection ie, immune system.

Question 5.
Can you recall meiosis and indicate at what stage a recombinant DNA is made?
Answer:
Pachytene stage of prophase I by crossing over.

Question 6.
Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?
Answer:
Reporter enzyme can differentiate recombinants from non-recombinants on the basis of their ability to produce specific color in the presence of chromogenic substrate. ArDNA is inserted within the coding sequence of the enzyme, galactosidase.

This results into inactivation f the enzyme which is referred to as insertional inactivation. The presence of a chromogenic substrate gives blue colored colonies, if the plasmid in the bacteria does not have an insert.

Presence of insert results into insertional inactivation of the-galactosidase and the colonies do not produce any colour. These are identified as recombinant colonies.

Plus Two Botany Biotechnology: Principles and Processes Multiple Choice Questions and Answers

Question 1.
The linking of antibiotic resistance gene with the plasmid vector became possible with
(a) DNA ligase
(b) Endonucleases
(c) DNA polymerase
(d) Exonucleases
Answer:
(a) DNA ligase

Question 2.
The construction of the first recombinant DNA was done by using the native plasmid of
(a) E.coli
(b) Salmonella typhimurium
(c) Bacillus thuringiensis
(d) yeast
Answer:
(b) Salmonella typhimurium

Question 3.
Which of the following is used as a best genetic vector in plants?
(a) Bacillus thuringiensis
(b) Agrobacterium tumefaciens
(c) Pseudomonas putida
(d) None of the above
Answer:
(b) Agrobacterium tumefaciens

Question 4.
One of the key factors, which makes the plasmid, the vector in genetic engineering?
(a) It is resistant to antibiotics
(b) It is resistant to restriction enzymes
(c) It has the ability to carry a foreign gene
(d) It has the ability to cause infection in the host
Answer:
(c) It has the ability to carry a foreign gene

Question 5.
A clone is
(a) heterozygote obtained asexually
(b) homozygote obtained asexually
(c) heterozygote produced by sexual methods
(d) homozygote produced by sexual methods
Answer:
(b) homozygote obtained asexually

Question 6.
In recombinant DNA technique, the term vector refers to
(a) donor DNA is identified and picked up through eletrophoresis
(b) plasmid, transfers DNA into living cell
(c) collection of entire genome in form of plasmid
(d) enzyme, cuts the DNA at specific sites
Answer:
(b) plasmid, transfers DNA into living cell

Question 7.
The enzyme employed for amplification of DNA during PCR is commercially obtained from
(a) Streptococcus pyogenes
(b) Bacillus licheniformis
(c) Trichodermapallidum
(d) Thermusaquaticus
Answer:
(d) Thermusaquaticus

Question 8.
The enzyme used for annealing the cut DNA segments is
(a) DNA ligase
(b) Helicase
(c) Topoisomerase
(d) Polymerase
Answer:
(d) Polymerase

Question 9.
How does PCR serve the purpose of early diagnosis?
(a) By detecting very low amounts of DNA by amplification
(b) It is a powerful technique to identify man genetic disorders
(c) To detect mutations is genes in suspected cancerpatients
(d) All the above
Answer:
(d) All the above

Question 10.
Enzyme used in the addition of nucleotides in DNA replication is
(a) catalase
(b) DNA polymerase
(c) nuclease
(d) RNA polymrerase
Answer:
(b) DNA polymerase

Question 11.
Importance of restriction endonuclease enzyme is to cut
(a) RNA strands at specific site
(b) DNA strands at specific site
(c) Ends of DNA strands
(d) none of the above
Answer:
(b) DNA strands at specific site

Question 12.
Large amount of recombinant protein is produced in
(a) tissue culture
(b) bioreactor
(c) somatic hybridization
(d) genetic engineering
Answer:
(b) bioreactor

Question 13.
Polymerase enzyme in the replication process to produce 1 billion copies of DNA is
(a) RNA polymerase 1
(b) DNA polymerase 1
(c) DNA polymerase 11
(d) taq polymerase
Answer:
(d) taq polymerase

Question 14.
Digested and undigested fragments of DNA can be observed in elecrophoresis by
(a) Ethidium bromide
(b) CFC
(c) Ethidium chloride
(d) acetyl chloride
Answer:
(a) Ethidium bromide

Question 15.
In which step of DNA amplification DNA hybridization occurs
(a) denaturation
(b) extention
(c) annealing
(d) elongation
Answer:
(c) annealing

Question 16.
The plasimid of Agrobacterium is
(a) Ti plasmid
(b) F1 plasmid
(c) T plasmid
(d) col E1
Answer:
(a) Ti plasmid

Question 17.
The ori of clonimg vector indicates
(a) cloning site
(b) restriction site
(c) replication site
(d) selectable marker site
Answer:
(c) replication site

Question 18.
Selectable marker of cloning vector plays an important role in
(a) identification of recombinants
(b) identification of non recombinants
(c) identification of recombinants from non recombinants
(d) none of the above
Answer:
(c) identification of recombinants from non recombinants

Question 19.
Coating of gold or tungsten particle with DNA is used in
(a) direct gene transfer
(b) indirect gene transfer
(c) both direct and indirect gene transfer
(d) none of the above
Answer:
(a) direct gene transfer

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Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 3 Strategies for Enhancement in Food Production

Plus Two Botany Strategies for Enhancement in Food Production One Mark Questions and Answers

Question 1.
Hisardale is a
(a) Good quality apple produced in Punjab
(b) Good quality sheep in Assam
(c) Good quality horse developed in Punjab by crossing Marino ewes and Bikaneri rams
(d) New breed of sheep developed in Punjab by crossing Marino rams and Bikaneri ewes
Answer:
(d)

Question 2.
During the period 1960-2000, wheat production increased from 11 million tones to 75 million tones while rice production went up from 35 million tones to 89.5 million tones. This was due to the development of varieties of wheat & rice possess the character
(a) Small
(b) Dwarf
(c) Semi-dwarf
(d) Long
Answer:
(c) Semi-dwarf

Question 3.
Give examples of some micro organisms that are used as SCP.
Answer:
Spirulina,
Methylophilus

Question 4.
Due to inbreeding depression fertility and productivity of animals are lost. Which is the best method used to overcome these?
Answer:
Outcrossing

Question 5.
Which part of the plant best suited for making virus free plantlet by in-vitro culture.
Answer:
Meristem

Question 6.
Find the odd one among the following. Sonalika, Jaya & Ratna, Prabhat Kranti, Kalyan Sona.
Answer:
Parbhani kranti

Question 7.
Hisaradale is a new breed of sheep developed in Punjab by cross-breeding. Name its parents.
Answer:
Hisardale is a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Marino rams

Question 8.
Sonalika and Kalyan Sona are varieties of
(a) Wheat
(b) Rice
(c) Millet
(d) Tobacco
Answer:
Nonalika and Kalyan Sona are varieties of wheat.

Question 9.
Which one of the following is not a fungal disease?
(a) Rust of wheat
(b) SmutofBajra
(c) Black rot of crucifers
(d) Red rot of sugarcane
Answer:
Black rot of crucifers is a bacterial disease

Question 10.
To isolate proteoplast, one needs
(a) Pectinase
(b) Cellulase
(c) Both pectinase and cellulas
(d) Chitinase
Answer:
(c) Both pectinase and cellulas

Question 11.
Which one of the following is a marine fish?
(a) Rohu
(b) Hilsa
(c) Catla
(d) Common Carp
Answer:
(b) Hilsa

Question 12.
Which one of the following products of apiculture is used in cosmetics and polishes?
(a) Honey
(b) Oil
(c) Wax
(d) Royal jelly
Answer:
(c)
Wax is a product of apiculture used in cosmetics and polishes.

Question 13.
More than 70 per cent of livestock population is in
(a) Denmark
(b) India
(c) China
(d) India and China
Answer:
(d)
More than 70% of the world livestock population is in India and China.

Question 14.
Male and female animals of two different related species are mated. In some cases, the progeny may combine the desirable features of both the parents. Name the type of hybridization?
Answer:
Interspecific hybridisation

Question 15.
Observe the relationship between the first two terms and fill in the blanks

1. IR-8: Rice
2. Atlas 66: …………

Answer:
Wheat

Question 16.
Name the disease resistant variety of wheat developed against Hill bunt disease.
Answer:
Himgiri

Question 17.
Fill in the blank……..is a wheat variety with high protein content and used as a donor for improving cultivated wheat.
Answer:
Atlas 66

Question 18.
Fill in the blank The part of plant used for virus free culture is……………..
Answer:
Meristem or shoot tip

Question 19.
For successful bee-keeping
(a) Knowledge of the nature and habits of bees, selection of suitable location for keeping the beehives
(b) Catching and hiving of Swarms(group of bees)
(c) Management of beehived during different season
(d) All of the above
Answer:
(d) All of the above

Question 20.
The main steps in breeding a new genetic variety of a crop are

1. Evaluation and selection of parents
2. Cross hybridization among the selected Parents
3. Collection of variability
4. Testing, release and commercialization of new cultivars
5. selection and testing of superior recombinants

(a) 1,2,3,4,5
(b) 1,4,5,2,3
(c) 3,1,2,5,4
(d) 3,2,5,1,4
Answer:
(c) 3,1,2,5,4

Question 21.
What is the common to following fishes Hilsa, Sardines, Mackerel, Pomfrets
(a) They are not edible
(b) Economically not viable
(c) Marine in nature
(d) All are fresh water fishes
Answer:
(c) Marine in nature

Question 22.
Give the term for the process of rearing honey bees.
Answer:
Apiculture

Question 23.
Name the varieties of cauliflowers which is resistant to black rot and curl blight black rot.
Answer:
Pusa shubhra and pusa snowball.

Question 24.
Mention the strategy used to increase homozygosity in cattle for desired traits.
Answer:
Inbreeding

Question 25.
Which part of the plant best suited for making virus free plantlet by in-vitro culture.
Answer:
Meristem

Question 26.
Find the odd one among the following and justify. Sonalika, Jaya & Ratna, Prabhat Kranti, Kalyan Sona.
Answer:
Parbhani kranti

Question 27.
When a farmer cultivated Bananas in a feild, most of banana plants were infected by virus. Can you suggest any method for propagation of virus free Banana plants.
Answer:
Meristem culture or shoot tip culture.

Question 28.
Define inbreeding depression. What is its danger?
Answer:
Continuous – Inbreeding without selection leads to loss of fertility & productivity.

Question 29.
Fill in the blanks using appropriate words: Interspecific hybrid produced by the cross between

Answer:
Mule

Question 30.
Fill in the blank________virus created a scare in the country and drastically affected egg and chicken consumption.
Answer:
Bird Flu Virus

Question 31.
Hisardale is a new breed of sheep developed in Punjab through
(a) Out crossing
(b) Outbreeding
(c) Crossing breeding
(d) Interspecific hybridisation
Answer:
(c) Crossing breeding

Question 32.
Male and female animals of two different related species are mated. In some cases, the progeny may combine the desirable features of both the parents. Name the type of hybridization?
Answer:
Interspecific hybridisation

Question 33.
______is the common species of honeybee in India.
Answer:
Apis indica

Question 34.
Carefully read the statements given below related to the steps in plant breeding. Choose the correct sequence.

1. Testing and commercialization of new variety
2. Evaluation and selection of parents
3. Selecting and testing superior recombinants
4. Cross hybridization among the selected parents
5. Collection of variability

(a) 5,2,4,3,1
(b) 1,4,3,5,2
(c) 2,3,4,5,1
(d) 4,5,3,2,1
Answer:
(a) 5,2,4,3,1

Question 35.
Name the disease resistant variety of wheat developed against Hill bunt disease.
Answer:
Himgiri

Question 36.
Fill in the blank. Plants produced through micropropagation are genetically identical to the orginal plant from which they were grown are known as________
Answer:
Somaclones.

Question 37.
Fill in the blank_______is a wheat variety with high protein content and used as a donor for improving cultivated wheat.
Answer:
Atlass 66

Plus Two Botany Strategies for Enhancement in Food Production Two Mark Questions and Answers

Question 1.
Plant breeders mostly use apical buds as explants in rapid propagation of sugarcane and banana. Write its significance.
Answer:
The apical bud is a meristem which is free of vims. By using these meristem as ‘explants’ in tissue culture large number of virus free – healthy plants can be obtained within a short period.

Question 2.
Following are the steps in MOET programme for herd improvement in which a cow has been Administered hormones with FSH life activities. Arrange steps in their correct sequence.
(a) Transferred to a surrogate mother
(b) It is either mated with elite bull or artificially Inseminated
(c) Fertilized egg at 32 cell stage are recovered non surgically
(d) It produces 6 to 8 eggs instead of one egg which they normally yield per cycle.
Answer:
(d) It produces 6- 8 egg cells instead of one egg per cycle.
(b) It is either mated with elite bull or artificially inseminated.
(c) Fertilised eggs at 32 celled stage are recovered non surgically.
(a) Transferred to a surrogate mother.

Question 3.
Name any four hybrid varieties of crop plants which have been developed in India.
Answer:
Jaya & Ratna variety of rice Sonalika & Kalyansona variety wheat, Pusa A4 variety of bhindi, Pusasadabahar variety of chilly.

Question 4.
Micro organisms are used to make proteins to meet the demand of food for increasing populations.

1. Name an alternate source of proteins for animal and human nutrition.
2. Is this protein harmful to the environment. Justify.

Answer:
1. SCP – Single Cell Protein eg: Spirulina.

2. In this process microbs are grown on an industrial scale as a source of good protein. Spirulina can be grown easily on materials like waste water from potato processing plant (containing starch), straw, Molases, The product is rich in protein, minerals, fat, carbohydrates & vitamin. This process reduces environmental pollution.

Question 5.
Nature of explants influence the quality of plants formed using tissue culture.

1. What is meant by explants?
2. Can you evaluate the above given statements?

Answer:

1. Any part of the plant used for micropropagation in vitro is called explants.
2. Meristems (apical and axillary) are free of virus. By using meristems as explants in tissue culture virus free healthy plants can be produced in large number within short duration.

Question 6.
Name any four hybrid varieties of crop.
Answer:

1. Himgiri – Wheat
2. Pusaswarnim – Brassica
3. Pusashubhra – Cauliflower
4. Pusakomal – Cow pea

Question 7.
When the farmercultivated Bananas in his field, most of the banana plants were infected by virus. Can you suggest any method for the propagation of healthy virus free banana plants?
Answer:
Although the plant is infected with virus, the meristem (apical bud) is free of virus. Hence remove the meritstjem and grow it into in-vitro to obtain virus free plants. Thus large number of healthy plants can be produced within short period by the method of micropropagation.

Question 8.
The idea of tissue culture originated from the concept of totipotency.

1. What is meant by it?
2. Name the chemical substance present in nutrient medium used as carbon source

Answer:

1. The inherent capacity of a cell to give rise to a whole plant is called tolipotency.
2. Sucrose

Question 9.
Biofortification is the most practical approach to improve the health of people

1. What is biofortification
2. Give four examples of biofortified crops released by IARI, New Delhi.

Answer:
1. It is the breeding crops with higher levels of vitamins and minerals, higher protein and healthier fats.

2. four examples of biofortified crops released by IARI, New Delhi:

• vitamin A-enriched carrots, spinach, pumpkin;
• vitamin C enriched bitter gourd, bathua, ustard,tomato;
• Iron and calcium enriched spinach and bathua;
• Protein enriched beans – broad, lablab, French and garden peas

Question 10.
Inbreeding strategy follows mating of superior male and superior female. Write down the criteria for selection of superior in the case of cattle.
Answer:
Superior males i.e the bull which gives rise to superior progeny and superior females i.e cow or buffalo that produces more milk per lactation.

Question 11.
Nature of explants influence the quality of plants formed using tissue culture

1. What are expfSnts?
2. Evaluate the above statement.

Answer:
1. Any part of a plant taken out (Egstem, leaf, root etc.) and grown in a test tube, under sterile conditions in special nutrient media.

2. It is a special mode of asexual reproduction in which all new plants formed are qualitatively and qualitatively similar to the parent(maintaining the desirable characters).

Question 12.
Beekeeping is the old age cottage industry that is very significant commercially

1. Name the useful products obtained
2. Why does a beekeeper keep beehives in crop fields during flowering period?

Answer:
1. Honey and Bee wax.

2. a beekeeper keep beehives in crop fields during flowering period:

• To increase the chances of pollination
• To increase the yield of honey.

Question 13.

1. Mention the property that enables the explants to regenerate into a new plant
2. A banana, herb is virus infected. Describe the method that will help in obtaining healthy banana plant form diseased plant.

Answer:

1. Totipotency
2. Extract the Meristem (apical and axillary) and grow it in vitro to obtain vims free banana plants.

Question 14.
Honey collection improves when beehives are kept in crop fields during flowering seasons. Explain.
Answer:
Bees are the pollination of many crops. Keeping beehives in crop fields during flowering period increases pollination and improve the honey yield. It is beneficial both for crop yield and honey yield.

Question 15.
Jersey is an important breed of cattle

1. Define breed
2. Differentiate between inbreeding and outbreeding

Answer:
1. A group of animals related by descent and similar in most characters like general appearance, feature, size, configuration etc. are called a breed.

2. Inbreeding – The mating of more closely related individuals within the same breed for 4-6 generations.

3. Out breeding – Breeding of the unrelated animals of the same breed but have no common ancestors for 4 – 6 generations.

Question 16.
What is the major advantage of producing plant by micro propagation?
Answer:
Micropropagation is a tissue culture technique which enables us to get unlimited number of plants in a limited space and short time.

Question 17.
When inbreeding depression becomes a problem, how can we overcome the issue?
Answer:
Firstly select animals from inbreed population and mate them with unrelated superior animals of the same breed (Outcrossing)). This helps to restore fertility and yield.

Question 18.
Match the following column A column B

Answer:
1(d), 2(a), 3(b), 4(c)

Question 19.
To improve the chances of successful production of hybrids, MOET is employed.

1. Expand MOET
2. Explain the steps involved in MOET

Answer:

1. Multiple Ovulation Embryo Transfer Technology
2. steps involved in MOET

• A cow is administered with FSH hormones, it induce follicular maturation and super ovulation.
• They produce 6-8 egg instead of one egg per cycle.
• Cow is mated with elite bull or artificially inseminated.
• Zygote at 8-32 cells are recovered non surgically and transferred to surrogate mother.
• The genetic mother is available for another round of super ovulation.

Question 20.
Give one example each of variety developed against white rust and bacterial blight.
Answer:

• White rust – Pusa Swarnim
• Bacterial blight – Pusa Komal

Question 21.
Observe the statements given below:

1. High yielding disease resistant wheat
2. Semi-dwarf variety of rice developed in Taiwan
3. Semi-dwarf variety of rice developed in India
4. Semi-dwarf variety rice developed in Philippines Fill up column B using the above statements.

Answer:

1. High yielding disease resistant wheat
2. Semi-dwarf variety of rice developed in Philippines
3. Semi-dwarf variety of rice developed in Taiwan
4. Semi-dwarf variety of rice developed in India.

Question 22.
Observe the table and fill a, b, c and d.

Answer:
(a) Pusa sadabahar
(b) Brassica
(c) Black rot/curl blight black rot
(d) Pusa komal

Question 23.
Construct a table with column-A Crop, and Column – B Variety using the hints given below. Hints – Wheat, Brassica, Cow pea, Cauliflower, PusaSwamim, PusaShubhra, Himgiri, PusaKomal
Answer:

Question 24.

1. In mung bean, two varieties are developed through mutation breeding for disease resistance. Name the disease for which the varieties are produced.
2. Name two agents that induce mutation.

Answer:

1. Resistance against yellow mosaic virus
2. Resistance to powdery mildew chemicals, gamma radiation.

Question 25.
Parbhanikranthi is a resistant variety of bhindi.

1. Which disease this breed is resistant to?
2. Name the scientific name of parbhani kranthi.

Answer:

1. Yellow mosaic virus
2. Abelmoschus esculentus

Question 26.
Observe the terms given below. Arrange then in the order of crop, variety, and insect pests in three columns. Pusa Gaurav, Aphids, Shoot and fruit borer, Brassica, PusaSem 3, Okra, PusaSawani, Pusa A-4
Answer:

Question 27.
The most practical means to improve public health is biofortification.

1. What do you mean by biofortification.
2. List out its main objectives.

Answer:
1. It is the Breeding crops with higher levels of vitamins, minerals, higher protiens and healtheir fats
2. objectives:

• protein content and quality
• oil content and quality.
• vitamin content
• micronutrient and mineral content

Question 28.

1. Indian agricultural institute, New Delhi developed vegetables with enriched vitamin and minerals.
2. Write two examples of vitamin A, iron and calcium enriched vegetables.

Answer:

1. Vitamin A enriched-Carrot, pumpkin
2. Iron and calcium enriched Spinach and bathua.

Question 29.
Explant, totipotency, micropropagation are terms very commonly used in tissue culture. Explain each terms.
Answer:
1. Explant: Any plant part taken for tissue culture
2. Totipotency: Capacity to generate whole plant from any cell
3. MicroPropaaation: Propagation of thousands of plants through tissue culture.

Question 30.
Pomato is a somatic hybrid. How this is developed?
Answer:
It is developed through following steps

• Isolation of single cell each from potato and tomato.
• Digestion of the cell wall using enzymes.
• Isolate the protoplast.
• Fuse to get hybrid protoplast. This can be grown to form a new plant.

Question 31.
Distinguish between the following. Apiculture and Pisciculture.
Answer:
Apiculture or Bee keeping is the maintenance of hives of honeybees for the production of honey. Pisciculture aims to increase the production of fishes.

Question 32.
Name two semi-dwarf rice and wheat varieties developed in India.
Answer:

1. Semi-dwarf rice – Java & Ratna
2. Semi-dwarf wheat – Sonalika & Kalyansona.

Question 33.
In some animals productivity is lost due to continuous inbreeding process

1. Name the breeding strategy is used to overcome productivity loss
2. Name the breading technique used to produce heterozygous offsprings

Answer:

1. Outcrossing
2. Cross breeding

Question 34.
Healthy plants are obtained from diseased plants by an important tissue culture technique.

1. Name it.
2. Which is the nutritive substance used as carbon source?

Answer:

1. Meristem culture
2. Sucrose

Question 35.
In 2000 hybrid Maize with higher levels of amino acid developed by plant breeding method

1. Name the strategy used
2. Give an example for protein-rich variety developed

Answer:

1. biofortification
2. Atlas 66

Question 36.
In 1960 the grain production of our country has increased due to the introduction of semi dwarf rice and wheat varieties.

1. Name the world renowned scientist has worked behind the Green Revolution program
2. Give an example for two rice varieties developed in India

Answer:

1. Norman E Borlaug
2. Jaya and Ratna

Question 37.
In Ayurvedic medicine and honey is very important to treat many diseases

1. Which is the most common species of bees used?
2. What are the significance of Apiculture?

Answer:

1. Apis indica
2. It helps to increase Honey yield, pollination efficiency and crop yield.

Question 38.
Name any five hybrid varieties of crop plants which have been developed in India
Answer:
The five hybrid varieties of crop plants which have been developed in India are:
Crop Plant Hybrid Variety

1. Wheat – Sonalika and Kalian sona
2. Rice – Jaya and Ratna
3. Cauliflower – Pusa shubra and Pusa snowball K-1
4. Cowpea – Pusa komal
5. Mustard – Pusaswarnim

Question 39.
What is the major advantage of producing plants by micropropagation?
Answer:
Micropropagation is a method of producing new plants in a short duration using plant tissue culture. Some major advantages of micropropagation are as follows:

1. Micropropagation helps in the propagation of a large number of plants in a short span of time.
2. The plants produced are identical to the mother plant.

Question 40.
How is a somatic hybrid different from a hybrid?
Answer:
Isolated protoplasts from two different varieties of plants can be fused to get hybrid protoplasts, which can be further grown to form a new hybrid plant that is called somatic hybrid.

Question 41.
What is emasculation? Why and when is it done
Answer:
Removal of anther from a bisexual flower is called emasculation. It is used to avoid self-pollination and is used in artificial hybridisation programme. It is done before the dehiscence of anther.

Question 42.
Plants raised through tissue cultures are clones of the ‘parent’ plant. Discuss the utility of these plants.
Answer:
Plant raised through tissue cultures are clones of the parent plant that means they are genetically identical to the original plant. They are utilised for maintaining a desirable trait of parent.

Question 43.

1. The shift from grain to meat diets creates more demands for cereals. Why?
2. A250 kg cow produces 200g of protein per day but 250g of Methylophillus methylotrophus can produce 25 tonnes of protein. Name this emerging area of research. Explain its benefits.

Answer:
1. It takes 3-10 kg of grain to produce 1 kg of meat using animal farming. That is why cereals demand increases.

2. Spirulina can be easily grown on starch, molasses etc. and can make food which is rich in proteins, minerals, fats, carbohydrates and vitamins. This could be a good alternative for dealing with the problem of malnutrition.

Question 44.
Observe the statements given below:

1. High yielding disease resistant wheat
2. Semi-dwarf variety of rice developed in Taiwan
3. Semi-dwarf variety of rice developed in India
4. Semi-dwarf variety rice developed in Philippines

Fill up column- B using the above statements.

Answer:

1. High yielding disease resistarit wheat
2. Semi -dwarf variety of rice developed in Philippines
3. Semi-dwarf variety of rice developed in Taiwan
4. Semi -dwarf variety of rice developed in India

Question 45.
Observe the table and fill a, b, c and d.

Answer:
(a) Pusa sadabahar
(b) Brassica
(c) Black rot/curl blight black rot
(d) Pusa komal

Question 46.
parbhani kranthi is a resistant variety of bhindi.

1. Which disease this breed is resistant to?
2. Name the scientific name of parbhani kranthi.

Answer:

1. Yellow mosaic vims
2. Abelmoschus esculentus

Plus Two Botany Strategies for Enhancement in Food Production Three Mark Questions and Answers

Question 1.
Poultry Farm Management of chicken, ducks, turkey and geese for food or their eggs

1. What are the important points to remember on poultry farming.
2. Name the causative organism of bird flu.

Answer:
1. poultry farming:

• Maintain disease free condition in farm.
• Provide proper feed and water.

2. Virus (H₅ N₁)

Question 2.
Your neighbor owned a diary farm. For better diary farm management what advise can you give for him?
Answer:
Dairy farm management includes processes and systems that increase yield and improve quality of milk.

It includes selection of good breeds having high yielding potential, resistance to diseases they have to be housed well, should have adequate water, maintained disease free, feeding should be in a scientific manner(in the quality and quantity of fodder), maintaining cleanliness and hygiene during milking, storage and transport of the milk and its products, and require regular visit of a veterinary doctor.

Question 3.
Pusagaura, pusaA-4, Himagiri, pusacomal are some hybrid varieties developed through plant breeding. Sumesh get this information from a magazine. But he did not know the steps of plant breeding through which these varieties are produced. Can you help him?
Answer:
The main steps of plant breeding are

• Collection of variability
• Evaluation and selection of parents:
• Cross hybridisation among the selected parents:
• Selection and testing of superior recombinants:
• Testing, release and commercialisation of new cultivars.

Question 4.
Match the following.

Answer:

Question 5.
Breeding technique that help to improve cattle population in India, some breeds are good in milk yielding and disease resistance

1. What is cross breeding?
2. What advantage does it confer?
3. Give one example.

Answer:
1. Cross breeding is the mating between animals of different breeds. It involves mating of superior males of one breed with superior females of another breed.

2. This method allows the desirable qualities of two different breeds to be combined. Thus the hybrid progeny will have desirable traits of both the breeds.

3. Eg-Hisardale is a new breed of sheep developed by crossing Bikaneri ewes and Marino rams.

Question 6.
Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields and disease resistance. Write’the major steps in breeding a new variety of crop.
Answer:
The steps involved in plant breeding are:
1. Collection of variability:
Collection and preservation of different wild varieties, species and relatives of cultivated species and evaluation of their characteristics.

2. Evaluation and selection of parents:
Evaluation of germplasm helps to identify plants with desirable characters and are selected as parents for hybridization.

3. Cross hybridisation among the selected plants:
The two parents selected are artificially hybridized and producing hybrid with desirable character.

4. Seletion and testing of superior recombinants:
The hybrids obtained are tested for superior character and are self pollinated for several generations till they reach a state of uniformity.

5. Testing release and commercialisation of new cultivars:
The selected lines are evaluated and the performance are recorded and is compared to the best available local cultivar and released as a new variety.

Question 7.
It is suggested to supply Atlas-66 variety of Wheat grains to the malnutrient communities.

1. Name the technology used to produce Atlas 66?
2. Explain it
3. Give four examples of biofortified crops released by IARI, New Delhi.

Answer:
1. Biofortification.

2. It is the breeding of crop with higher level of vitamin& Minerals or higher protein & healthier fats. It is the most practical means to improve public health.

3. IARI, New Delhi, released vitamin enriched carrots, Spinach, pumkin vitamin c enriched bitter gourd, mustard,tomato& calcium enriched spinach & protein enriched beans – Broad lablab, French beans & garden peas.

Question 8.
Somatic hybridization technique is used to raise hybrid plants with combined characters of two different plants.

1. How is it achieved?
2. Give an example
3. What are soma clones?

Answer:
1. Protoplast can’ijeHsolated from cells by digesting their walls using enzymes. Somatic hybridization is the fusion of isolated protoplasts from two different varieties of plants having desirable characters.

The fusion results in the formation of hybrid protoplast. These protoplast are further grown into a new plant. The plants obtained are called somatic hybrids.

2. Pomato

3. Plants got during micro propagation (tissue culture) are genetically identical to the original plant from where they are grown.

Question 9.
Inbreeding increases homozygosity and causes inbreeding depression.

1. What you meant by inbreeding depression.
2. Name the progenies obtained through this process with selection.

Answer:
1. Inbreeding is the mating of more closely related individuals of the same breed. Continued inbreeding leads to increasing homozygozity and ultimately results in the reduction of fertility and productivity.

2. Purelines.

Question 10.
‘Apiculture’ has become an established income-generating industry ______

1. What is Apiculture?
2. Which is the most commonly used species?
3. What are the matters one should know before starting apiculture?

Answer:
1. Apiculture is the maintenance of hives of honeybees for the production of honey.
2. The commonly used species of honeybee is Apis indica.
3. The following points are considered for successful bee keeping.

• Knowledge of the nature and habits of bees.
• Selection of suitable location for keeping the bee hives.
• Catching and hiving of swarms(group of bees).
• Management of bee hives during different seasons.

Question 11.
To improve changes of successful production of hybrids other means are also used. MOET is one such programme.

1. What is MOET?
2. Write down the steps used for herd improvement.

Answer:
1. MOET is multiple ovulation embryo transfer technology. It is the controlled breeding method. It is done to improve the chances of successful production of hybrids.

2. steps used for herd improvement:

• Cow is given hormones with FSH-like activity
• To induce follicular maturation and super ovulation
• It produce 6-8 eggs/cycle.
• This animal is then mated with an elite bull or artificially inseminated.
• The fertilised eggs at 8-32 cells stages, are removed and transferred to surrogate mother.

Question 12.
Pusa-gaurav, pusa A-4, Himagiri, pusa comal are some hybrid varieties developed through plant breeding. Sumesh get this information from a magazine. But he did not know the steps of plant breeding.

1. Write down the steps of plant breeding
2. Name the revolution that leads to the food production in World.

Answer:
1. The main steps of plant breeding are

• Collection of variability
• Evaluation and selection of parents
• Cross hybridisation among the selected parents
• Selection and testing of superior recombinants
• Testing, release and commercialisation of new cultivars

2. Green revolution

Question 13.
Bee-keeping is the maintenance of hives honey bees for the production of honey. Illustrate the important steps for successful bee keeping.
Answer:

1. Knowledge of the nature and habit of
2. Selection of suitable location for keeping the beehives.
3. Catching and hiving of swarms.
4. Management of beehives during different seasons
5. Handling and collection of honey and bee wax.

Question 14.
Breeding between animals of the same breed is called inbreeding. Write the steps of inbreeding.
Answer:

1. Identifies superior male and female of the same breed.
2. Mate them in pairs.
3. Identifies the superior male and female of the progeny for further mating.
4. Select the best breed.

Question 15.
Write the advantages and disadvantages of inbreeding.
Answer:

Question 16.
Why does a beekeeper keep beehives in crop fields during the flowering periods?
Answer:
Bees are available during flowering periods, as they feed on the pollen and nectar of flowers.

1. It increases pollination efficiency and crop yield.
2. It also improves honey yield.

Question 17.
Raju is working in an Agricultural Research station and is directed to provide large number of plants like banana, orchids, haploid varieties of water melon and two medicinal plants whose leaves and roots are used as medicines.

1. Write the most suitable method that Raju can adopt.
2. Give any two advantages of this method.

Answer:
1. Micro propagation
It is the tissue culture method used to produce large no. of plants within a short period.

2. advantages of this method:

• The plants are genetically identical to the original plant from which they grown (soma clones).
• The plants must be virus free as meristems are used as explants.

Plus Two Botany Strategies for Enhancement in Food Production NCERT Questions and Answers

Question 1.
If your family owned a dairy farm. What measures would you undertake to improve the quality and quantity of milk production?
Answer:
To improve the quality and quantity of milk production the following steps are to be taken.

• Selection of good breeds having high yielding potential and disease resistance.
• The cattle should be housed well with adequate water and maintained disease free.
• The feeding of cattle should be in scientific manner – giving emphasis on quality and quantity of fodder.
• Cleanliness and hygiene (both of cattle and handlers) should be given paramount importance to milking, storage and transport of milk.

Question 2.
Name any five hybrid varieties of crop.
Answer:

1. Himgiri – Wheat
2. Pusaswarnim – Brassica
3. Pusashubhra – Cauliflower
4. Pusakomal – Cow pea
5. PusaSadabahar-Chilli

Question 3.
Name the methods employed in a animal breeding. According to you which of the method is best. Why?
Answer:
The methods employed in animal breeding are:

1. Inbreeding
2. Outbreeding such as out crossing, cross breeding and interspecific hybridization.
3. Controlled breeding such as artificial insemination and multiple ovulation embryo transfer technique.

Artificial insemination method of controlled breeding is best because it ensures good quality progeny and it is economic also.

Question 4.
What is apiculture? How is it important is our lives?
Answer:
Apiculture:
Rearing of honey bees for the commercial production of honey and bee wax. Apiculture is a low cost investment and highly profitable. It provides honey, wax and act as pollinator of many crops.

Question 5.
Discuss the role of fishery in enhancement of food production.
Answer:
A large section of the Indian population uses fish and many other aquatic animals such as crabs, lobsters, prawns etc. as food. The fish serve as a chief source of protein, has very little fat, carries a good amount of minerals, vitamins and iodine. Thus fisheries plays significant role in enhancement of food production.

Question 6.
Explain what is meant by biofortification.
Answer:
Biofortification:
Breeding crops with higher levels of vitamins and minerals or higher protein and healthier fats is called biofortification. The biofortification is done with improvement of public health as the primary goal.

Question 7.
Which part of the plant is best suited for making virus-free plants and why?
Answer:
The apical and axillary meristem are the best suited parts of plant for the production of virus-free plants. These parts are generally free from virus due to the absence of vascular tissue through which vims are transported.

Question 8.
What is the major advantage of producing plant by micro propagation?
Answer:
Micropropagation is a tissue culture technique which enables us to get unlimited number of plants in a limited space and short time.

Question 9.
Find out what the various components of the medium used for propagation of an explant in vitro are?
Answer:
The major components of the medium are water, inorganic salts, sucrose (source of carbon and energy), vitamins, amino acids, and growth hormones like auxins, cytokinins etc.

• Other compounds like casein, coconut milk, yeast extract etc. may be added for specific purposes.
• If required a gelling agent agar is added to the liquid medium for its solidification.

Question 10.
Name any five hybrid varieties of crop plants which have been developed in India.
Answer:

1. Wheat – Himgiri
2. Rice – Jaya, Ratna
3. Brassica – PusaSwarnim
4. Cow pea – Pusa Comal
5. Chilli – PusaSadabahar

Plus Two Botany Strategies for Enhancement in Food Production Multiple Choice Questions and Answers

Question 1.
Hybrid vigour is mostly due to
(a) superiority of all the genes
(b) homozygosity of pure characters
(c) heterozygosity
(d) mixing of recessive characters only
Answer:
(c) heterozygosity

Question 2.
Breeding of crops which high levels of minerals, vitamins and proteins is called
(a) Somatic hybridisation
(b) Biofortification
(c) Biomagnification
(d) Micropropagation
Answer:
(c) Biomagnification

Question 3.
Disease resistant crop is obtained by
(a) crossing with new varieties
(b) crossing with wild varieties
(c) injecting with organic compounds
(d) crossing with recessive varieties
Answer:
(b) crossing with wild varieties

Question 4.
In maize, hybrid vigour is exploited by
(a) bombarding the seeds with DNA
(b) crossing of two superior desirable parental lines
(c) harvesting seeds from the most productive plants
(d) inducing mutations
Answer:
(b) crossing of two superior desirable parental lines

Question 5.
Wonder wheat is new wheat variety developed by
(a) Mexico’s international Wheat and Maize Improvement Centre
(b) Indian National Botanical Research Institute
(c) Australian Crop Improvement Centre
(d) African Crop Improvement Centre
Answer:
(a) Mexico’s international Wheat and Maize Improvement Centre

Question 6.
The terminator gene technology causes
(a) failure of seed setting after one generation
(b) breakage of seed dormancy
(c) early flowering in plants
(d) death of microorganisms in soil
Answer:
(a) failure of seed setting after one generation

Question 7.
Study the following columns.

Answer:
(c) 3 4 1 2

Question 8.
The high yielding hybrid crop varieties to exploit hybrid vigour, the farmers need to purchase fresh hybrid seed every year because.
(a) hybridvigour is not long-standing due to inbreeding depression
(b) they are not allowed to grow their own seed
(c) it is always associated with increased heterozygosity
(d) always associated with increased homozygosity
Answer:
(c) it is always associated with increased heterozygosity

Question 9.
In crop improvement programme, haploids are of great importance because they
(a) grow better under adverse conditions
(b) are useful in the study of meiosis
(c) requires only abgut half the amount of chemical fertilizers compared to diploids
(d) give homozygous lines
Answer:
(d) give homozygous lines

Question 10.
Match the following columns and choose the correct option.

Answer:
(b) 1 2 4 5

Question 11.
Three crops that contribute maximum to global food grain production are
(a) Wheat, rice and maize
(b) Wheat, maize and sorghum
(c) rice, maize and Sorghum
(d) Wheat, rice and barley
Answer:
(a) Wheat, rice and maize

Question 12.
India’s wheat yield revolution in the 1960s was possible primarily due to
(a) hybrid seeds
(b) increased chlorophyll content
(c) mutations resulting in plant height reduction
(d) quantitative trait mutations
Answer:
(c) mutations resulting in plant height reduction

Question 13.
Mule is a product of
(a) breeding
(b) inter generic hybridisation
(c) hybridization
(d) interspecific hybridisation
Answer:
(d) interspecific hybridisation

Question 14.
Protoplasts of two different species are fused in
(a) micro-propagation
(b) somatic hybridisation
(c) clonal propagation
(d) organography
Answer:
(b) somatic hybridisation

Question 15.
Removal of anthers of some flowers during plant breeding is
(a) emasculation
(b) anthesis
(c) pollination
(d) for collection of pollen
Answer:
(a) emasculation

Question 16.
The type of hormone used for MOET is
(a) insulin
(b) LH
(c) FSH
(d) LTH
Answer:
(c) FSH

17. The species of insect very common in apiculture is
(a) Apisindica
(b) Apisdorsata
(c) Both a & b
(d) none of the above
Answer:
(a) Apisindica

Question 18.
The industry mainly responsible for the catching, rearing and selling of fish and its products come under
(a) Pisciculture
(b) Aquaculture
(c) Silviculture
(d) Apiculture
Answer:
(a) Pisciculture

Question 19.
Which method is used to overcome inbreeding depression
(a) Intra specific hybridization
(b) self pollination
(c) outbreeding
(d) intra varietal hybridization
Answer:
(c) outbreeding

Question 20.
Bird flu is caused by
(a) H₁N₁
(b) H₅N₁
(c) H₃N₁
(d) H₂N₁
Answer:
(b) H₅N₁

Question 21.
Disease free plants are produced by
(a) somatic hybridization
(b) meristem culture
(c) protoplast culture
(d) embryo culture
Answer:
(b) meristem culture

Question 22.
Atlas 66 is the variety of
(a) wheat
(b) rice
(c) maize
(d) sorghum
Answer:
(a) wheat

Question 23.
Somaclones shows
(a) similarity with parents
(b) dissimilarity with parents
(c) similarity among offsprings but not with parents
(d) none of the above
Answer:
(a) similarity with parents

Question 24.
Green revolution mainly aims for growing
(a) disease resistance variety
(b) semi dwarf variety
(c) self fertilizing variety
(d) none of the above
Answer:
(b) semi dwarf variety

Question 25.
Hisardale is the superior breed of sheep developed by
(a) cross breeding
(b) genetic engineering
(c) somatic hybridization
(d) inbreeding
Answer:
(a) cross breeding

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Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 2 Sexual Reproduction in Flowering Plants

Plus Two Botany Sexual Reproduction in Flowering Plants One Mark Questions and Answers

Question 1.
Types of pollination in Commelina is
(a) chasmogamy
(b) geitonogamy
(c) xenogamy
(d) cleistogamy
Answer:
(d) cleistogamy

Question 2.
When pollen is transferred from another of a flower to stigma of the another flower of the of the same plant, it is referred to as
(a) allogamy
(b) xenogamy
(c) geitonogamy
(d) autogamy
Answer:
(c) geitonogamy

Question 3.
For plant breeding purposes: Pollens are stored at -196°C. What is the purpose behind it?
Answer:
Stored pollens can be used as pollen banks in crop breeding programmes.

Question 4.
Pollen tube enters the embryo sac through
(a) Integument
(b) Micropyle
(c) Calaza
(d) Funicle
Answer:
(b) Micropyle

Question 5.
In flowering plants, fertilization occur in
(a) Ovary
(b) Embryo sac
(c) Nucellus
(d) Ovule
Answer:
(b) Embryo sac

Question 6.
The source of food for developing embryo is
(a) Nucellus
(b) Ovule
(c) Endosperm
(d) Anther
Answer:
(c) Endosperm

Question 7.
Out of megaspre tetrad, the functional megaspore is
(a) Any megaspore
(b) Middle megaspore
(c) Micropylar megaspore
(d) Chalazal megaspre
Answer:
(d) Chalazal megaspre

Question 8.
How many megaspore mothe cell are produced in a nuclellus
(a) 3
(b) 1
(c) 2
(d) 4
Answer:
(b) 1

Question 9.
During the development of monosporic development of embryo sac, the nucleus of the functional megaspore divides
(a) Two times
(b) Three times
(c) Onetime
(d) Repeatedly
Answer:
(b) Three times

Question 10.
Cross pollination has an advantage of
(a) Mutation
(b) polyploidy formation
(c) Genetic recombination
(d) Crossing over
Answer:
(c) Genetic recombination

Question 11.
Unisexual flowers prevent
(a) Pollination
(b) Breeding
(c) Self-pollination
(d) Cross fertilization
Answer:
(c) Self-pollination

Question 12.
The function of the filiform apparatus is
(a) To nourish the pollen grain
(b) To guide the entry of pollen tube
(c) To develop pollen tube
(d) To carry pollen tube through style
Answer:
(b) To guide the entry of pollen tube

Question 13.
Find the odd one. Hilum, Funicle, Intine, Integuments
Answer:
Intine

Question 14.
Choose the correctly matched pair.
(a) Coleorrhiza – Hollow foliar structure
(b) Perisperm- Remanents of nucellus
(c) Proembryo – mature embryo
Answer:
(b) Perisperm – Remanents of nucellus

Question 15.
Choose the correct answer. The layer of microsporangium that nourishes the developing pollen grains is
(a) Endothecium
(b) Tapetum
(c) Middle layer
(d) Epidermis
Answer:
(b) Tapetum

Question 16.
A typical angiosperm embryo sac at maturity is.
(a) 7 nucleate 8 celled
(b) 8 nucleate 8 celled
(c) 7 nucleate 7 celled
(d) 8 nucleate 7 celled
Answer:
(d) 8 nucleate 7 celled

Question 17.
The process of formation of fruits without fertilization is called.
(a) Parthenogenesis
(b) Parthenocarpy
(c) Apomixis
(d) Autogamy
Answer:
(b) Parthenocarpy

Question 18.
Identify the wrong statements regarding post – fertilization development.
(a) The ovary wall develops into pericarp
(b) The outer integument of ovule develops into tegmen
(c) The fusion nucleus (triple nucleus) develops into endosperm
(d) The ovule develops into seed
Answer:
(b) The outer integument of ovule develops into tegmen

Question 19.
Dicot emdryo consists of
(a) radicle and plumule
(b) radicle;plumule, cotyledons and sometimes endosperm
(c) radicle and plumule, cotyledons and tegmen
(d) radicle andplumule, cotyledons tegmentesta
Answer:
(b) radicle,plumule, cotyledons and sometimes endosperm

Question 20.
These process are necessary for the complete development of male gametophyte from pollen mother cell
(a) one meiotic and two mitotic divisions
(b) one meiotic cell division and one meiotic cell division
(c) two meiotic cell division and one mitotic cell division
(d) two meiotic cell division
Answer:
(a) one meiotic and two mitotic divisions

Question 21.
A bilobeddithecus anther has 100 microspore mother cells per micro sporangium. How many male gametophytes this anther can produce?
Answer:
400 male gametophytes

Question 22.
An anther with malfunctioning tapetum often failsto produce viable male gametophytes. Give one reason.
Answer:
Tapetum nourishes developing pollen grains

Plus Two Botany Sexual Reproduction in Flowering Plants Two Mark Questions and Answers

Question 1.
Pollen grains are well preserved as fossil for many years due to some characteristics

1. Name the chemical substance present in pollen wall promote such preservation
2. Give reasons.

Answer:

1. sporopollenin
2. It is the most resistant organic material and can withstand high temperatures, strong acids, and alkali. No enzymes can degrade sporopollenin.

Question 2.
One time fertilization is the characteristic feature of majority of plants but angiosperm show two times of fertilization

1. Two fusion occurs are different. Name it and write down the number of nuclei involved in such process
2. Name the products and ploidy.

Answer:

1. Syngamy. Two nuclei Triple fusion, three nuclei
2. Zygote (2n), PEN (3n)

Question 3.
Commelina, viola, and oxalis that carries both chasmogamous and Cliestogamy flowers.

1. Find out the main differences between them.
2. Give the significance of Cliestogamy.

Answer:

1. Chasmogamous flowers with exposed anthers and stigma. Cleistogamous flowers do not open at all.

2. significance of Cliestogamy:

• It ensures self pollination.
• Purity of characters is maintained.

Question 4.

1. Geitonogamy is a functional cross-pollination but not genetically. Justify?
2. In Papaya, Autogamy and Geitonogamy do not occur. Give reason.

Answer:
1. Geitonogamy is functionally cross-pollination because transfer pollen takesplace between different flowers of same plant that bear same genetic makeup.

2. Papaya is dioecios plants, because, the male and female flowers are present on different plants, which prevent autogamy and geitonogamy.

Question 5.
Wind pollination is common in grasses and water pollination in vallisneria. Give the features of these plants to facilitate pollination.
Answer:
1. Grasses

• Pollen grains are light weight and non-sticky
• Stigama is feathery.

2. Vallisneria

• Flowers do not produce nector and fragrance.
• Female flowers reach the surface of water by long stalk.

Question 6.
In most plants continuous self-pollination leads to inbreeding depression while in others certain devices help to discourage self pollination. Give any four devices.
Answer:

1. Pollen release and stigma receptivity are not at the same time.
2. Another and stigma are placed at different positions.
3. Self-incompatibility.
4. Production of unisexual flowers.

Question 7.
The micropyle remains as a small pore in the seed coat. What is its role?
Answer:
Micropyle facilitates the entry of oxygen and water into the seed during germination.

Question 8.
Draw the diagram of a typical dicot embryo and label the parts like plumule, cotyledons, radicle, and root cap.
Answer:

Question 9.
Observe the developmental stages given below and answer the following.

1. Name the process.
2. Label the stages A, B, C & D

Answer:

1. Embryogenesis (Formation of embryo)
2. A-proembryo B-globular stage C-heart shaped stage D-mature stage

Question 10.
Apomictic seeds are important in agriculture. Do you agree? Give reason.
Answer:
Yes. These seeds are formed without fertilisation hence there is no genetic variation .This feature is helpful to preserve the desirable characters for many years.

Question 11.
Give the technical terms for the following

1. Produce seeds without fertilization
2. Persistent nucellus

Answer:

1. Parthenocarpy
2. Perisperm

Question 12.
Emasculation may not be necessary. Yet bagging is necessary. Justify giving the condition when such a thing can happen.
Answer:
When the flower chosen is unisexual (female), there is no need for emasculation. Yet bagging is necessary to prevent contamination of the stigma with unwanted pollen grains.

Question 13.
Banana is a true fruit and also a parthenocarpic fruit. Justify.
Answer:
Since banana fruit is formed from ovary it is true fruit. It is parthenocarpic because the ovary develops into fruit without fertilization.

Question 14.
Arrange the following terms in the correct development sequence: Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell
Answer:
Sporogenous tissue → Pollen mother cell → Microspore tetrad → Pollen grain.

Question 15.
Some peoples live in area are subjected to allergic disease due to pollen grains.

1. Give an example for plants that produce pollen of above type?
2. Give an example for two disease?

Answer:

1. Parthenium (Carrot grass)
2. Asthma and Bronchitis

Question 16.
Typical angiosperm embryo sac is 7 celled and 8 nucleate. This condition occurs due to the development of megaspore mother cell

1. How many meiotic and mitotic division takes place
2. What you mean by monosporic development?

Answer:

1. Single meiotic division and 3 mitotic division.
2. Single functional megaspore develops into mature embryo sac.

Question 17.
Pollen allergy that causes chronic respiratory disorders in men like asthma and bronchitis. Name the causative plant.
Answer:
Parthenium or carrot grass

Question 18.
Some pollen grains cannot germinate on stigmatic surface due to the loss of viability

1. Name the factors influence the viability of pollen
2. How do the pollen grains can keep up for many years

Answer:

1. Temperature and humidity
2. Pollen grains are kept in Pollen Bank at-196 degree Celsius in liquid nitrogen.

Question 19.
Pollen tube growth occurs through the stylar region and reach micropyie of ovule. Name the special cellular thickening that guides Pollen tube
Answer:
Filiform apparatus

Question 20.
Pollengrains of many plants are found to be allergic.

1. Do they have any benefits other than the involvement in reproduction? Explain
2. Give examples.

Answer:
1. Pollen grains are rich in nutrients. In recent years pollen tablets are used as food supplements. It is used in western countries in the form of syrup and tablets. Pollen consumption has been claimed to increase the performance of athletes and race horses.

2. Parthenium, acasia

Question 21.
Zygote development leads to the formation of embryo.

1. Name the nutritive tissue that helps in the development of embryo
2. What will be the ploidy of such a tissue

Answer:

1. endosperm
2. endosperm is triploid

Question 22.
Suppose you are given four flowers namely maize, vallisneria, sunflower, and zostera.

1. State the mode of pollination in each flower.
2. Differentiate between cleistogamous and chasmogamous flowers.

Answer:

1. Maize-wind pollination
Vallisnaria-water pollination Sunflower – insect pollination

2. Cliestogamous – closed flower
Chamogamous – opened flower

Question 23.
A close relationship exist between a species of moth and the plant Yucca, where both species moth and Yucca cannot complete their life cycles without each other. Justify it.
Answer:
The moth deposits its eggs in the locule of the ovary of the Yucca flower. Flower in turn gets cross pollinated by the moth. The larvae of the moth come out of the eggs as the seeds starts developing.

Question 24.
Coconut and groundnut are oil yielding crops, point out the difference in the structure of seed.
Answer:
Coconut is an endospermous seed. Reserve food materials like fat, oil, etc. are stored in endosperm, in which the prominent part is endosperm and small sized embryo is situated at one end of the endosperm.

Question 25.
Seeds are formed in angiosperms when male and female gametes get fused. But in some plants seeds are produced without the fusion of gametes.

1. Name the process,
2. Comment.

Answer:
1. Apomixis

2. Apomixis is a form of asexual reproduction which mimics sexual reproduction. Seeds are produced from a diploid egg cell without reduction division and fertilization. Nucellar tissue surrounding the embryosac develops into an embryo.

Question 26.
In market, seedless grapes are high priced than seeded grapes. Give the method used to develop the former.
Answer:
The seedless grapes are developed through induced parthenocarpy.

Question 27.
Plant A with combined desired characters that are inherited from parents. Plant B with desired characters are pure. Find out the types of pollination leads to accurance of characters in both A & B.
Answer:
In plant A, cross-pollination leads to the occurance of mixing of characters while in Plant B self pollination and self-fertilisation results the pure character.

Question 28.
If the diploid chromosome number of a plant is 24. Find out the number of chromosomes in synergid, Antipodal, and endosperm.
Answer:
Here 2n=24, n=12 so the number of chromosomes in synergids and antipodals are 12 each. But endosperm is triploid, chromosome number is 36.

Question 29.
Pollination is aided by biotic and abiotic agents. Identify the type of pollination in Vallisneria, coconut, and grass.
Answer:

• Vallisneria -water pollination
• Coconut and grass-wind pollination.

Question 30.
Give the technical terms for the following

1. Produce seeds without fertilization
2. Persistent nucellus
3. Cotyledons of grass family
4. Protective sheath of radical.

Answer:

1. Parthenocarpy
2. Perisperm
3. Scutellum
4. Coleorhizae

Question 31.
Why do you think the zygote is dormant for some time in a fertilized ovule?
Answer:
This is because the embryo develops only after the formation of endosperm. So the zygote wait for endosperm formation which supplies food material for developing embryo.

Question 32.
In some plants self-pollination is prevented by genetic mechanism of either pollen or pistil

1. Name the process
2. Why does such process not lead to seed formation?

Answer:

1. Self incompatibility
2. It is because of interaction between the chemicals of the pollen and those of stigma (Pollen-pistil interaction)

Question 33.
If one can induce parthenicarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why?
Answer:
Watermelon, Orange and lemon because in these fruits the seeds are scattered within their edible parts and if seed are removed they become more valuable.

Question 34.
Embryosac or female gametophyte of angiospemn is 7 celled and 8 nucleate How many haploid cells are present in micropylar and chalazal part of female gametophyte of a flowering plant? Name them.
Answer:
Chalazal-Antipodals3, micropylar- Synergids 2, Egg cell 1.

Question 35.
If you squeeze seed of orange you might observe many embryos of different sizes? How is it possible?
Answer:
In orange, nucellar cells surrounding embryosac start dividing, protrude into embryosac and form many embryos.

Question 36.
If the chromosome number of plant species is 16. What would be the chromosome number and ploidy level of

1. microspore mother cell
2. endosperm cells

Answer:

1. Microspore mother cell 16
2. Endosperm cell 24

Question 37.
Observe the flow chart given below. Fill in the blank 1 and 2. Write the relevance of the process indicated as 1.

Answer:

1. Bagging
2. Artificial pollination In bagging the entry of unwanted pollen to stigmatic surface is prevented

Question 38.
Apple and mango are fruits. But they are formed in different ways. How are they formed?
Answer:
Apple is called a false fruit because the thalamus develops into fruit. Here ovary is not involved. Mango is a fruit because it is formed from ovary

Question 39.
The synergids have special cellular thickening. Name the thickening and write its function.
Answer:
Filiform apparatus
It guides the pollen tube into the synergid

Question 40.
Analyse the table and fill in the blank.

Answer:

1. Thalamus also contributes to fruit formation
2. True fruit
3. Parthenocarpy
4. Banana

Question 41.

Answer:

1. a – Micropyle
2. b – Embryo sac
3. c – Nucellus
4. d – Chalaza

Question 42.
The embryo sac development in majority of flowering plants is monosporic development. Explain this type of embryo sac development.
Answer:
In this type a single megaspore mother cell of the nucellus differentiates in the ovule. Here Megaspore mother cell undergoes meiosis to form four megaspores, out of four, one megaspore becomes functional, while the other three degenerate. The functional megaspore develops into fully matured embryo sac.

Question 43.
Self-incompatibility and dioecious condition are two devices for discouraging self-pollination in plants. Explain the two.
Answer:
Self-incompatibility – In this, pollen fail to germinate on stigma/pistil of the same flower. This is due genetic mechanism of either male parent or female parent. Dioecious condition – It is the occurrence of Male and female flowers on different plants.

Question 44.
Peculiarities of certain parts of the ovule are given below. Name the parts.

1. Protective envelops of the ovule
2. Stalk of the ovule
3. The layer of cells within the integuments
4. Junction between ovule and funicle

Answer:

1. Integuments
2. Funicle
3. Nucellus
4. Hilum

Question 45.
Geitonogamy and xenogamy are two types of pollination. Differentiate between the two.
Answer:
1. Geitonogamy
It is the transfer of pollen grains from the anther to the stigma of another flower of the same plant.

2. Xenogamy
It is the transfer of pollen grains from anther to the stigma of a different plant.

Question 46.
The inner most wall layer of microsporangium is tapetum. It is multinucleate. Justify this statement.
Answer:
Out of four wall layers of anther, tapetum is the innermost layer that nourishes the developing pollen grains.

Question 47.
Peculiarities of two types of seeds are given below. Identify the two types of seeds and give example for each.

1. Endosperm completely used by embryo.
2. Endosperm not completely used by embryo.

Answer:
1. Non-albuminous/Ex-albuminous
Eg: Pea, Groundunt, etc.

2. Albuminous
Eg: Wheat, Maize, Barley, Castor, etc.

Question 48.
The embryo of monocotyledons and dicotyledons show difference in structure. Explain the structure of dicot embryo.
Answer:
A dicot embryo has an embryonal axis and two cotyledons. The portion of embryonal axis above the level of cotyledons is the epicotyl.it terminates in plumule. The Cylindrical portion below the level of cotyledons is hypocotyl, it terminates at its lower end in radicle.

Question 49.
Occurrence of more than one embryo in a seed is called polyembryony.

1. Give two examples of polyembryony.
2. How does polyembryony occur?

Answer:

1. Citrus and mango
2. Some of the nucellar cells surrounding the embryo sac is diploid that start dividing and develop into the embryos.

Question 50.
Mature pollen grain has a vegetative cell and a generative cell. Write the peculiarities of the two cells.
Answer:
Vegetative cell – It is the bigger cell possess abundant food reserve, Large irregularly shaped nucleus. Generative cell It is the small cell that floats in the cytoplasm of vegetative cell possess dense cytoplasm and a nucleus.

Question 51.
Endosperm develops from the primary endosperm nucleus. Explain the process of endosperm development.
Answer:
The PEN undergoes successive nuclear divisions that give rise to free nuclei later cell wall formation occurs and becomes cellular eg coconut.

Question 52.
Geitonogamy is similar to autogamy. Justify this statement.
Answer:
In geitonogamy pollen grains come from the same plant. Both Autogamy and geitonogamy are come under self pollination.

Question 53.
Apomixis is an asexual form of reproduction,that mimics sexual reproduction. Substantiate this statement.
Answer:
Apomixis is a kind of asexual reproduction in which seeds are produced without fertilization. By retaining the seed habit, it mimics to sexual reproduction.

Question 54.
Observe the relationship between the first two terms and fill in the blanks.

1. Exine: Sporopollenin; Intine : …………..
2. Pistils fused: Syncarpous; Pistils free: ………….
3. Zygote : 2n ; Endosperm : …………..

Answer:

1. Cellulose and pectin
2. Apocarpous
3. 3n

Plus Two Botany Sexual Reproduction in Flowering Plants Three Mark Questions and Answers

Question 1.
Pollen grains in angiosperms ace not motile. They have to be carried to the stigma by external agents.

1. Name the process of transfer of pollen grains.
2. Write the name of three such agents.
3. Explain how it takes place in vallisnaria.

Answer:
1. Transfer of pollen grains from the anther to the stigma is called pollination.

2. Wind water and animals

3. In vallisneria the female flowers reach the surface of water by long stalk and the male flowers or pollen grains are released to the surface of water and are carried by water currents to the female flower and fertilization takes place.

Question 2.
Ramu while observing the C.S. of anther of Datura through a microscope, found fourwall layers.

1. Name the layers.
2. Write down its functions.

Answer:
1. layers:

• epidermis
• endothecium
• middle layer
• tapetum

2. The outer three layers perform protective function. Tapetum nourishes the developing pollen.

Question 3.
In flowering plants microspores are formed by meiosis and are haploid tetrads

1. How will you show the formation of microspores and male gametophyte from microspore mother cells
2. Write down the formation of embryosac and monosporic development?

Answer:
1. In the anther each cell of sporogenous tissue act as microspore mother cells (2n) which undergoes meiosis and forms four microspores (n) which are arranged in a cluster of four cells, ie.

microspore tetrad. When the anther matures the microspore dissociates from each other and develop into pollen grains. The pollen grains represents male gametophyte.

2. The nucellus of the ovule one cell is enlarged and act as megaspore mother cell (2n) which undergoes meiosis and results four megaspores (n) one of the megaspore is functional while the other three degenerates.

Only the functional megaspore develop into the embryo sac. Thus embryo sac formation from a single megaspore is called ‘monosporic’.

Question 4.
Fill up the blanks by observing the first pair.
1. Plumule: Shoot
………….: Root

2. Shoot apex: Coleoptile
Root apex: ………..

3. Ovary: Pericarp
Nucellus: ……………

4. Zygote: Embryo
…………: Endosperm

5. Syngamy: Zygote
……….: PEC

6. Ovule: Seed
…………: Seed coat

Answer:

1. Radicle
2. Coleorhiza
3. Perisperm
4. Primary Endosperm nucleus
5. Triple fusion
6. Integument

Question 5.
Diagrammatic representation of mature embryo sac is given.

1. Identify the cells that are involved in fertilization
2. Write the ploidy condition of that cells before and after fertilization.
3. Point out the role of ‘x’ in the diagram.

Answer:
1. Central cell (with two palar nuclei )and egg

2. Before fertilization – Central cell – 2n/ n+n
After fertilization – Central cell – 3n
Before fertilization – egg – n
After fertilization – egg. 2n.

3. Filiform apparatus – guides the pollen tubes into the synergids at the time of pollen germination prior to fertilization.

Question 6.
Double fertilization is the characteristic feature of angiosperms.

1. What does it mean?
2. Name the products and process.

Answer:1. It is the fertilization takes place two times.
2.

Question 7.
Haploidy, diploidy, and tripoloidy are the ploidy level of angiosperm plant parts from a seed is given below.

1. Find out the chromosome status of each part.

• Integuments outer, inner
• Nucellus
• Secondary nucleus
• Zygote

2. How will you give explanation to reduction of chromosome number from diploid to haploid?

Answer:
1. chromosome status of each part:

• Integuments outer and inner-2n(diploid)
• Nucellus-2n (diploid)
• Secondary nucleus-3n (triploid)
• Zygote-2n (diploid)

2. Chromosome number reduced due to reduction division or meiosis.

Question 8.
A bisexual self pollinating flowering plant has chromosome number 76, in its somatic cells.

1. What will be the chromosome number of its nucellus, synergids, zygote, and endosperm?
2. What is the advantage of cross pollination over self pollination?
3. Give any 2 characteristics of wind pollinated flowers.

Answer:
1. Nucellus is diploid; chromosome no is 76 Synergids are haploid;chromosome no. is 38 Zygoye is diploid; chromosome no. is 76 Endosperm is triploid its chromosome no. is 114.

2. Sexual reproduction brings about genetic recombination and results in the better Survival of the species.

3. The flowers are small and inconspicuous .they are formed in clusters. Lightweight Pollens are produced in large amount. Stigma is long and hairy.

Question 9.
Tender coconut has liquid endosperm inside it. But matured it has only solid endosperm

1. Write down the auction of endosperm.
2. How will you differentiate liquid endosperm from solid endosperm.
3. Name the part of embryo pushes deep into endosperm.

Answer:

1. Provide nutrion.
2. Liquid endosperm- provide nutrition for the development of zygote into mature embryo. Solid endosperm- provide nutrition for the future development of embryo.
3. Suspensor.

Question 10.
60% of angiosperms, pollen grains shed at 2 celled stage, but in some species pollen grains are shed at 3 celled stage.

1. Distinguish between 2 celled and 3 celled stage of pollen grains?
2. Give the significance of germ pore of exine surface

Answer:

1. In 2 celled stage pollen grains contains two cells – bigger vegetative cell and smaller generative cell. In 3 celled stage, pollen grains contains 3 cells vegetative cell and 2 male gametes
2. Germ pore is the opening through which pollen tube come out during pollen germination

Question 11.
In angiosperm 7-celled and 8-nucleate embryosac is formed from single megapore mother cell.

1. Name the process
2. Name the 3 – nuclei found in chalazal part of embryosac
3. Which is the opening of ovule that helps in the entry of pollen tube?

Answer:

1. Megasprogenesis
2. Antipodals
3. Micropyle

Question 12.
Pollen grains in angiosperms are not motile. They have to be carried to the stigma by external agents.

1. Name the process of transfer of pollen grains.
2. Write the name of three such agents.
3. Explain how it takes place in vallisnaria.

Answer:

1. Pollination.
2. Wind, water, and animals
3. In vallisnaria, mature female flower reach the surface of water by the long stalk in the same time male flowers or pollen grains are released on to the surface of water. Stigma collect the pollen grains and come inside the water.

Question 13.
Flowering plants have major devices to discourage self pollination and to increase cross pollination. Point out any four devices.
Answer:
1. Pollen release and stigma receptivity are not synchronised, ie. either the pollen is released before stigma become receptive or stigma becomes receptive much before the release of pollen.

2. In some plants the anther and stigma are placed at different positions so that pollen cannot come in contact with the stigma of the same flower.

3. Self pollination is prevented by self-incompatibility which is a genetic mechanism that prevents the pollen of the same flower or flowers of the same plant from fertilizing the ovules.

4. Production of unisexual flowers also prevents autogamy but not geitonogamy. Dioceous plants prevents both autogamy and geitonogamy.

Question 14.
Maize consists of nectar less flowers but in or chids flowers are nectary and attractive.

1. Distinguish the characteristics of both flowers based on the agents involved in the pollen transfer.
2. Some organisms involved in pollination produce foul odor. Name.

Answer:
1. Maize is a wind pollinated plant. The flowers produce large amount of light and non sticky pollen grains which helps in transportation through wind.

They possess well exposed stamens and large and feathery stigma to easily capture pollen grains. There is a single ovule in an ovary and arranged in compact inflorescence.

Orchid is an insect pollinated plant. It produce large conspicuous flowers, the small flowers are produced in clusters.

The large flowers are colourful, fragrant and rich in nectar. The insects are attracted by colour and fragrance and are often rewarded by nectar and pollen produced by the flower.

2. Flies and beetles.

Question 15.
Wind is an abiotic agent that helps in pollination. Write any six features of wind pollinated flowers.
Answer:

1. Pollen grains are light
2. Non – sticky pollen grains
3. Well exposed stamens
4. Large, feathery stigma
5. Single ovule in each ovary
6. Numerous flowers packed into inflorescence

Question 16.
Observe the figure given below and explain its structure.

Answer:
It is the structure of pollen grain, it has an outer hard layer called exine that possess prominent apertures called germ pores through which pollen tube come out.

The inner wall layer is continuous called intine. Pollen grain has two cells, a large vegetative cell, and a small generative cell.

Question 17.
Observe the diagram given below.

a) Copy the diagram, and label antipodals and synergids.
b) Explain double fertilization.
Answer:
1.

2. At first, one of the male gametes fuses with egg cell to form a diploid zygote. This is called syngamy. The other male gamete fuses with the polar nuclei to form primary endosperm nucleus (PEN). This is called triple fusion. Thus, two types of fusion occur in the embryo sac called Double fertilization.

Plus Two Botany Sexual Reproduction in Flowering Plants NCERT Questions and Answers

Question 1.
Differences between microsporogenesis and megasporogenesis. Which type of cell division occurs during this events? Name the structures formed at the end of these two events.
Answer:

• In both, the events meiosis cell division occurs.
• Microsporogenesis results in the formation of microspores while megasporogenesis forms megaspores.

Question 2.
Arrange the following terms in the correct development sequence: Pollen grain, sporogenous, microspore tetrad, pollen mother cell, male gametes.
Answer:
Sporogenous tissue ’!Pollen mother cell’!Microspore tetrad’!Pollen grain’!Male garnets.

Question 3.
What is meant by monosporic development of female gametophyte?
Answer:
The formation of female gametophyte or embryo sac from a single functional megaspore is called monosporic. The nucleus of functional megaspore undergoes 3 successive mitotic divisions to form haploid nuclei.

Question 4.
With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
Answer:
Embryo sac is an oval multicellular structure which contains 8 nuclei but 7 cells.

Question 5.
What are chasmogamous flowers? Can cross¬pollination occur in cleistogamous flowers? Give reasons for your answer.
Answer:
Chasmogamous flowers have exposed anthers and stigma. Cross-pollination cannot occur in cleistogamous flowers, as such flowers do not open at all.

Question 6.
Mention two strategies evolved to prevent self-pollination in flowers.
Answer:
Flowering plants have developed many devices to discourage self-pollination and to encourage cross-pollination.

Plus Two Botany Sexual Reproduction in Flowering Plants Multiple Choice Questions and Answers

Question 1.
Apomictic embryos in Citrus arise from
(a) synergids
(b) maternalsporophytic tissue in ovule
(c) antipodal cells
(d) diploid egg
Answer:
(b) maternalsporophytic tissue in ovule

Question 2.
Wind pollinated flowers are
(a) small, brightly coloured, producing large number of pollen grains
(b) small, producing large number of dry pollen grains
(c) large producing abundant nectar and pollen
(d) small, producing nectar and dry pollen
Answer:
(b) small, producing large number of dry pollen grains

Question 3.
Which of the following statements about sporopollenin is false?
(a) Exine is made up of sporopollenin
(b) Sporopollenin is one of the resistant organic materials
(c) Exine has apertures called germ pores where sporopollenin is present
(d) sporopollenin can withstand high temperatures and strong acids
(e) No enzyme that degradessporopollenin is so far known
Answer:
(c) Exine has apertures called germ pores where sporopollenin is present

Question 4.
Egg apparatus of angiosperms consist of
(a) one synergid and two egg cells
(b) two synergid and one egg cells
(c) one central cell, two synergid, and three antipodal cells
(d) one egg cell, two polar nuclei, and three antipodal cells
Answer:
(b) two synergid and one egg cells

Question 5.
In some organisms, karyokinesis is not followed by cytokinesis as a result of which, multinucleate condition arises leading to the formation of syncytium. The perfect example for this is
(a) appearance of a furrow in cell membrane
(b) liquid endosperm in coconut
(c) sexual reproduction
(d) fertilization
Answer:
(b) liquid endosperm in coconut

Question 6.
During the formation of embryo sac, the functional megaspore undergoes
(a) two mitotic divisions
(b) two meiotic division
(c) three meiotic division
(d) three mitotic divisions
Answer:
(d) three mitotic divisions

Question 7.
One advantage of cleistogamy is
(a) it leads to greater genetic diversity
(b) seed dispersal is more efficient and widespread
(c) seed set is not dependent on pollinators
(d) each visit of a pollinator results in transfer of hundreds of pollen grains
Answer:
(c) seed set is not dependent on pollinators

Question 8.
Which one of the following statements is not true?
(a) Pollen grains are released from anthers at 2- celled state
(b) Sporogenous cell directly behaves as he megaspore mother cell
(c) Megaspore divides twice to form an eight nucleate embryo sac
(d) Egg and synergids always lie near the micropylar end of ovule
Answer:
(c) Megaspore divides twice to form an eight nucleate embryo sac

Question 9.
Sporopollenin is chemically
(a) homopolysaccharide
(b) fatty substance
(c) protein
(d) heteropolysaccharide
Answer:
(d) heteropolysaccharide

Question 10.
Which one of the following pairs of plant structures has haploid number of chromosomes?
(a) Megaspore mother cell and antipodal cells
(b) Egg cell and antipodal cells
(c) Nucellus and antipodal cells
(d) Egg nucleus and secondary nucleus
Answer:
(b) Egg cell and antipodal cells

Question 11.
What does the filiform apparatus do at the entrance into ovule?
(a) It helps in the entry of pollen tube into a synergid
(b) It prevents entry of more than one pollen tube into the embryo sac
(c) It brings about opening of the pollen tube
(d) It guides pollen tube from a synergid to egg
Answer:
(a) It helps in the entry of pollen tube into a synergid

Question 12.
Which of the following plant products is the hardest?
(a) Lignin
(b) Cutin
(c) Suberin
(d) Sporopollenin
Answer:
(d) Sporopollenin

Question 13.
A typical angiosperm embryo sac at maturity, is
(a) 4 – nucleate – 2 celled
(b) 8 – nucleate – 7 celled
(c) 4- nucleate – 4 celled
(d) 8 – nucleate – 2 celled
Answer:
(b) 8 – nucleate – 7 celled

Question 14.
Why sometimes, even diploid offspring is produced through parthenogenesis?
(a) When offspring is produced without fertilization of diploid egg cell
(b) When offspring is produced through fertilization of diploid egg cell
(c) When offspring is produced without fertilization of haploid egg cell
(d) When offspring is produced through fertilization of haploid egg cell
Answer:
(a) When offspring is produced without fertilization of diploid egg cell

Question 15.
Pollen grains are stored for long period without losing its viability in
(a) liquid nitrogen
(b) liquidsulphur
(c) liquidsulphur at-1960c
(d) liquidsulphur at-196.50c
Answer:
(a) liquid nitrogen

Question 16.
Filiform apparatus of an embryosac is located at
(a) wall of embryosac
(b) chalazal region
(c) micropylar region
(d) middle of polar nuclei
(e) none of the above
Answer:
(c) micropylar region

Question 17.
Double fertilization is very common in
(a) angiosperm
(b) gymnosperm
(c) pteridophytes
(d) bryophytes
Answer:
(a) angiosperm

Question 18.
In Citms and mango the polyembryony is the special feature of occurance of
(a) more than one embryo
(b) more than one zygote
(c) more than one embyosac
(d) all the above
Answer:
(d) all the above

Question 19.
Triple fusion takes place in angiosperm is due to
(a) fusion of three polar nuclei
(b) fusion of synergid and polar nuclei
(c) fusion of three haploid nuclei
(d) fusion of gametes
Answer:
(c) fusion of three haploid nuclei

Question 20.
In 40 percent of angiosperms, pollen grains are shed at
(a) 2-celled
(b) 3-celled
(c) 4-celled
(d) 5- celled
Answer:
(b) 3-celled

Question 21.
In artificial hybridization, bagging is done to
(a) avoid wanted pollen
(b) avoid unwanted pollen
(c) prevent the entry of unwanted pollinators
(d) allow the self-pollination
Answer:
(b) avoid unwanted pollen

Question 22.
How many mitotic divisions are required for the formation of mature embryosac
(a) 4
(b) 3
(c) 5
(d) 2
Answer:
(b) 3

Question 23.
The allergies and bronchial afflictions in some people often leading to chronic respiratory disorders. It is due to
(a) pollen of parthenium
(b) pollen of hibiscus
(c) pollen of Acasia
(d) both a and c
Answer:
(d) both a and c

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